WO2024011878A1 - Electrode assembly, battery cell, battery and electrical device - Google Patents

Abstract

An electrode assembly (13), a battery cell (40), a battery (100), and an electrical device. The electrode assembly (13) comprises a winding structure (14) and insulating members (4). The winding structure (14) comprises a first electrode sheet (1), a separator (3) and a second electrode sheet (2). The first electrode sheet (1) and the second electrode sheet (2) are separated by means of the separator (3), the first electrode sheet (1), the separator (3) and the second electrode sheet (2) are wound in a winding direction, the first electrode sheet (1) has end portions in the winding direction, the insulating members (4) are connected to the first electrode sheet (1), and the insulating members (4) wrap the end portions of the first electrode sheet (1), so that the first electrode sheet (1) is insulated from the second electrode sheet (2). The provided electrode assembly (13) can prevent the first electrode sheet (1) from overlapping with the second electrode sheet (2), thereby improving the safety performance of the battery (100).

Description

Electrode components, battery cells, batteries and electrical devices

Cross-references to related applications

This application claims priority to Chinese patent application 202221833857.8 titled "Electrode Assemblies, Battery Cells, Batteries and Electrical Devices" submitted on July 15, 2022. The entire content of this application is incorporated herein by reference.

Technical field

The present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery and an electrical device.

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.

In the existing technology, some battery cells use rolled electrode assemblies. In this type of electrode assembly, the metal substrate on the anode plate and the cathode cut surface are directly overlapped, thereby causing the risk of short-circuit failure and affecting the safety performance of the battery cells. .

Therefore, a new type of electrode assembly is urgently needed.

Utility model content

Embodiments of the present application provide an electrode assembly, a battery cell, a battery and an electrical device. The electrode assembly can avoid the risk of short circuit failure caused by overlap between pole pieces, and improves the safety performance of the battery cell.

In a first aspect, an electrode assembly is proposed according to an embodiment of the present application. The electrode assembly includes a winding structure and an insulator. The winding structure includes a first pole piece, a diaphragm, and a second pole piece. The first pole piece and the second pole The plates are separated by a diaphragm. The first pole piece, the diaphragm and the second pole piece are wound along the winding direction. The first pole piece has an end in the winding direction. An insulating piece is connected to the first pole piece. The insulating piece is wrapped It is arranged to cover the end of the first pole piece so that the first pole piece and the second pole piece are insulated.

In the above solution, an insulating member is provided on the end of the first pole piece, so that the end of the first pole piece is insulated from the outside world, thereby forming end protection for the first pole piece and preventing the first pole from being punctured after the diaphragm is punctured. The overlap between the pole piece and the second pole piece occurs at the end, which avoids the risk of short circuit caused by the electrical connection between the end of the first pole piece and the outside world, and improves the safety of the electrode assembly and the battery cells it is applied to during operation. performance.

In some embodiments, the first pole piece includes a first current collector and a first active material layer disposed on both sides of the first current collector, the end portion includes an end surface of the first current collector in the winding direction, and the insulating member is at least partially Cover the end face.

In the above solution, the insulating member needs to specifically cover the end face of the first current collector to avoid electrical interference caused by contact between the end face of the first current collector and the outside world, reduce the risk of failure caused by overlapping with the second pole piece, and provide the electrode assembly with security.

In some embodiments, the insulating member covers the end surface and at least part of the first active material layer disposed.

In the above solution, the insulating member not only covers the end surface to form insulating protection, but also covers at least part of the first active material layer, achieving full coverage of the end of the first pole piece and improving the stability of the connection between the insulating member and the end of the first pole piece. properties, reducing the risk of insulation parts falling off.

In some embodiments, the insulating member includes a side plate connected to the first pole piece and covering the end surface.

In the above solution, the insulating member can be connected through the side plate and cover the end surface of the first current collector. The side plate can be coupled with the end surface profile of the first current collector to facilitate connection while ensuring coverage of the end surface of the first current collector. Moreover, this method has a simple structure and is convenient for molding.

In some embodiments, in the thickness direction of the first pole piece, the extension length of the side plate is greater than the sum of the thickness of the first current collector and the thickness of the first active material layer.

In the above solution, by limiting the extension length of the side plate, the side plate covers both the first current collector and the first active material layer, thereby ensuring that the side plate can completely cover the first current collector in the thickness direction of the first pole piece. The end face avoids the exposure of local end faces and improves the reliability of insulation protection.

In some embodiments, the insulating member includes two end plates oppositely arranged in the thickness direction. The two end plates are connected to and enclosed by the side plates to form a frame structure. The side plates cover the end surface and the first active material layer, along the thickness direction. direction, the orthographic projection of the end plate covers part of the first active material layer.

In the above solution, two end plates are provided in the insulator and connected to the side plates respectively to form a frame structure. While the side plates can completely cover the end surfaces, the first active material layer will increase in the portion covered by the two end plates. The overall connection strength of the insulating parts improves the stability of the connection and reduces the risk of the insulating parts falling off.

In some embodiments, the side plate is a flat plate structure, and the two end plates are vertically connected to the side plates and enclosed to form a frame structure, and the insulating member is connected to the end surface and the first active material layer through the side plates.

In the above solution, a plan is provided in which the side plates have a flat structure. By setting the side plates into a flat structure and vertically connecting them to the two end plates, the side plates can be placed close to the end face of the first current collector, thereby improving the insulation. The stability is more consistent with the contour design of conventional pole pieces.

In some embodiments, the side plate is a tapered plate structure, and the side plate includes a first side part and a second side part. One end of the first side part and the second side part is respectively connected to the two end plates and the other end is arranged to intersect. , so that the insulation parts form a tapered frame structure.

In the above solution, another solution is provided in which the side plate is a tapered structure. The side plate is divided into a first side part and a second side part, and is arranged at a certain distance from the end face of the first current collector. It can also be used The end face is insulated from the outside world to improve safety performance and reflect the diversity of the structure.

In some embodiments, along the winding direction, the extension length of the two end plates is greater than or equal to 0.3 mm and less than or equal to 50 mm.

In the above solution, by limiting the extension length of the two end plates, the entire insulating member can not only meet the requirements for connection stability, but also ensure that the pole pieces are within the normal energy density range requirements.

In some embodiments, the extension length of the two end plates does not exceed 10 mm along the winding direction.

In the above solution, on the premise that the connection stability of the insulating parts is satisfied and the energy density is within the normal range, the extension length of the two end plates does not exceed 10mm, which saves materials and facilitates processing and molding.

In some embodiments, the absolute value of the difference in extension lengths of the two end plates in the winding direction is greater than zero.

In the above solution, during production and processing, the extension lengths of the two end plates can be made unequal, which improves the flexibility of the production process. At the same time, it also increases the diversity of the insulating parts structure to meet more connection needs.

In some embodiments, the insulating member includes two top plates oppositely arranged in the axial direction of the rolled structure. The two top plates are respectively connected to the two end plates and side plates and enclose to form a box structure. Along the axial direction of the rolled structure, In the axial direction, the top plate orthographic projection covers at least part of the first active material layer.

In the above solution, by setting two top plates facing each other in the axial direction, the insulating parts form a box structure as a whole. While ensuring that the insulating parts cover the end faces, the two additional top plates further improve the stability of the connection of the insulating parts and reduce their Risk of shedding.

In some embodiments, the top plate is a flat plate structure. The top plate, the end plates and the side plates are respectively connected vertically and enclosed to form a box structure. The top plate is arranged in contact with the top surface of the first active material layer.

In the above solution, a specific structural form of the box structure is provided. By setting the top plate as a flat plate structure and attached to the top surface of the first active material layer, the original insulating member is connected through three surfaces and is added to five. Surface connection further improves the stability of the overall connection of the insulating parts.

In some embodiments, the top plate is a tapered plate structure, and the top plate includes a first top and a second top. One end of the first top and the second top is respectively connected to the end plate and the other end is close to each other in the axial direction of the winding structure. Extending and intersecting, the top plate is spaced apart from the top surface of the first active material layer.

In the above solution, another specific structural form of the box structure is provided. By arranging the first top and the second top, the top plate of the insulating member is spaced apart from the top surface of the first active material layer, while ensuring that the side plate covers the end surface. At the same time, it also improves the stability of the axial connection.

In some embodiments, the side plate is a flat plate structure, and the two end plates are vertically connected to the side plates and enclosed to form a frame structure. The insulating member is connected to the end surface through the side plates. Along the winding direction, the end plates are connected to the first active material. The layers are arranged one after another, and in the thickness direction, the end plate is flush with the surface of the first active material layer facing away from the first current collector.

In the above solution, the insulating member is arranged flush with the first active material layer. The structure formed makes the pole piece without protrusions or step structures, the surface is smoother, the overall force is more uniform, and the winding and assembly are facilitated.

In some embodiments, the first pole piece has two ends in the winding direction, and the insulator is disposed on the two ends of the first pole piece.

In the above solution, insulating members can be provided at both ends of the first pole piece in the winding direction, and the two ends of the pole piece are insulated and protected at the same time, thereby avoiding the influence of the outside world on both ends and ensuring the safety of the pole piece. Performance is further guaranteed.

In some embodiments, the insulation member is formed in one piece.

In the above solution, in terms of processing technology, the insulating parts can be integrally formed, which simplifies the process steps, improves production efficiency, and saves manufacturing costs.

In a second aspect, the present application provides a battery cell, including the electrode assembly according to any embodiment of the first aspect.

In a third aspect, the present application provides a battery, including the battery cell as described above.

In a fourth aspect, the present application provides an electrical device, including the battery as described above.

The above description is only an overview of the technical solutions of the present application. In order to have a clearer understanding of the technical means of the present application, they can be implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and understandable. , the specific implementation methods of the present application are specifically listed below.

Description of 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 drawings described below are only some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application;

Figure 2 is an exploded structural diagram of a battery according to an embodiment of the present application;

Figure 3 is an exploded structural diagram of a battery cell according to an embodiment of the present application;

Figure 4 is a schematic structural diagram of a rolled electrode assembly according to an embodiment of the present application;

Figure 5 is a schematic structural diagram of the first pole piece according to the embodiment of the present application;

Figure 6 is a cross-sectional view along the direction A-A in Figure 5;

Figure 7 is a cross-sectional view structure along the B-B direction in Figure 5;

Figure 8 is another cross-sectional view structure along the B-B direction in Figure 5;

Figure 9 is another cross-sectional view structure along the B-B direction in Figure 5;

Figure 10 is a schematic structural diagram of another first pole piece according to the embodiment of the present application;

Figure 11 is a cross-sectional view structure along the C-C direction in Figure 10;

Figure 12 is another cross-sectional view structure along the C-C direction in Figure 10;

Figure 13 is a cross-sectional view structure along the D-D direction in Figure 10;

Figure 14 is a schematic structural diagram of another wound electrode assembly according to an embodiment of the present application.

Reference signs:

1000-vehicle; 100-battery; 200-controller; 300-motor;

10-battery module; 20-upper cover; 30-lower cover; 40-battery cell;

11-end cover; 11a-electrode terminal; 12-casing; 13-electrode assembly; 14-winding structure;

1-first pole piece; 2-second pole piece; 3-diaphragm; 4-insulation piece;

X-winding direction; Y-thickness direction; Z-axial direction;

101-the first current collector; 102-the first active material layer;

401-side plate; 4a-first side; 4b-second side; 4c-first top; 4d-second top;

402-end plate; 403-top plate.

In the drawings, identical components have the same reference numerals. The drawings are not drawn to actual scale.

Detailed ways

The embodiments of the present application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments. In the description of this application, it should be noted that, unless otherwise stated, "plurality" means more than two; the terms "upper", "lower", "left", "right", "inside", " The orientation or positional relationship indicated such as "outside" is only for the convenience of describing 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 of the present application. Application restrictions. Furthermore, the terms "first," "second," "third," etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable error range. "Parallel" is not parallel in the strict sense, but within the allowable error range.

Reference in this application to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the 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. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

The directional words appearing in the following description are the directions shown in the figures and do not limit the specific structure of the present application. In the description of this application, it should also be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. Detachable connection, or integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application may be understood based on specific circumstances.

The battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The current collector that is not coated with the positive electrode active material layer protrudes from the current collector that is coated with the positive electrode active material layer. The current collector coated with the positive electrode active material layer is laminated to form a positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector that is not coated with the negative electrode active material layer protrudes from the current collector that is coated with the negative electrode active material layer. The current collector coated with the negative electrode active material layer is laminated to serve as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc. In addition, the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.

The inventor noticed that the electrode assembly, especially the wound electrode assembly, has the risk of short-circuit failure during the molding and operation processes. The inventor further studied and found that the sides of the current collectors in the positive and negative electrode sheets are coated with active material layers, while the current collector end faces in the positive and negative electrode sheets are usually exposed, and their materials are usually metal. After lithium is precipitated from the negative electrode piece, it will pierce the separator, causing the current collector end faces of the negative electrode piece and the positive electrode piece to overlap, causing a short circuit between the electrode pieces, thereby causing the risk of failure and posing certain safety hazards. Therefore, the probability of short circuit failure caused by overlap between pole pieces can be reduced by covering the end surface of the current collector.

Based on the above considerations, in order to solve the problem of overlap failure between pole pieces, the inventor designed an electrode assembly after in-depth research. The electrode assembly includes a winding structure and an insulator. The winding structure includes a first pole piece, a diaphragm and The second pole piece, the first pole piece and the second pole piece are separated by a diaphragm. The first pole piece, the diaphragm and the second pole piece are wound along the winding direction. The first pole piece includes a first current collector and a The first active material layer of the first current collector has an insulating member connected to the first pole piece. The insulating member covers the end surface of the first current collector in the winding direction, so that the first pole piece and the second pole piece are insulated.

In the above solution, an insulating member is provided on the end surface of the first pole piece and the insulating member covers the first current collector of the first pole piece, so that the first current collector is insulated from the outside world and forms an insulator to the end surface of the first pole piece. Protection to prevent the first pole piece and the second pole piece from overlapping at the end face after the diaphragm is punctured, avoid the risk of short circuit caused by the first current collector end face being electrically connected to the outside world, and improve the efficiency of the electrode assembly and its application Safety performance of battery cells during operation.

The technical solutions described in the embodiments of this application are applicable to battery cells, batteries, and electrical devices using batteries.

The battery cells 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 electrode assembly, battery cell, battery, etc. disclosed in this application. In this way, overlapping short circuit of the positive and negative electrode plates in the electrode assembly can be avoided, the risk of battery failure can be reduced, and the safety of the battery can be improved.

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 Figures 2 and 3. Figure 2 is an exploded view of the battery 100 provided by some embodiments of the present application, and Figure 3 is an exploded view of the battery cell 40 provided by some embodiments of the present application. The battery 100 includes a case and battery cells 40 . In some embodiments, the box may include an upper cover 20 and a lower cover 30 . The upper cover 20 and the lower cover 30 cover each other. The upper cover 20 and the lower cover 30 jointly define an accommodation space for accommodating the battery cells 40 . The lower cover 30 can be a hollow structure with one end open, and the upper cover 20 can be a plate-like structure. The upper cover 20 covers the open side of the lower cover 30 so that the upper cover 20 and the lower cover 30 jointly define a receiving space; the upper cover 20 can be a plate-shaped structure. 20 and the lower cover 30 can also be hollow structures with one side open, and the open side of the upper cover 20 is closed with the open side of the lower cover 30 . Of course, the box formed by the upper cover 20 and the lower cover 30 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.

In the battery 100 , there may be a plurality of battery cells 40 , and the plurality of battery cells 40 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 40 are connected in series and in parallel. Multiple battery cells 40 can be directly connected in series or in parallel or mixed together, and then the whole composed of multiple battery cells 40 can be accommodated in the box; of course, the battery 100 can also be composed of multiple battery cells 40 connected in series first. They may be connected in parallel or mixed to form a battery module 10, and multiple battery modules 10 may be connected in series, parallel, or mixed to form a whole, and be accommodated in a box. 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 40 .

Each battery cell 40 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, but is not limited thereto. The battery cell 40 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes.

Please continue to refer to Figure 3. The battery cell 40 refers to the smallest unit that constitutes the battery. As shown in FIG. 3 , the battery cell 40 includes an end cover 11 , a housing 12 , an electrode assembly 13 and other functional components.

The end cap 11 refers to a component that covers the opening of the casing 12 to isolate the internal environment of the battery cell 40 from the external environment. Without limitation, the shape of the end cap 11 can be adapted to the shape of the housing 12 to fit the housing 12 . Optionally, the end cap 11 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 11 is less likely to deform when subjected to extrusion and collision, so that the battery cell 1 can have higher durability. Structural strength and safety performance can also be improved. The end cap 11 may be provided with functional components such as the electrode terminal 11a. The electrode terminal 11 a may be used to electrically connect with the electrode assembly 13 for outputting or inputting electric energy of the battery cell 40 . In some embodiments, the end cap 11 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 40 reaches a threshold. The end cap 11 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 layer may be provided inside the end cover 11 , and the insulating layer may be used to isolate the electrical connection components in the housing 12 from the end cover 11 to reduce the risk of short circuit. For example, the insulating layer may be plastic, rubber, etc.

The casing 12 is a component used to cooperate with the end cover 11 to form an internal environment of the battery cell 40 , wherein the formed internal environment can be used to accommodate the electrode assembly 13 , electrolyte, and other components. The housing 12 and the end cover 11 may be independent components, and an opening may be provided on the housing 12. The end cover 11 covers the opening at the opening to form the internal environment of the battery cell 40. Without limitation, the end cap 11 and the shell 12 can also be integrated. Specifically, the end cap 11 and the shell 12 can form a common connection surface before other components are put into the shell. When it is necessary to encapsulate the inside of the shell 12, Let the end cap 11 cover the outer shell 12 . The housing 12 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 12 can be determined according to the specific shape and size of the electrode assembly 13 . The outer casing 12 may be made of various 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 13 in this application may be a wound electrode assembly. Please refer to Figure 4. When winding the first pole piece 1, the second pole piece 2 and the separator 3, the first pole piece needs to be wound first. 1. The starting ends of the second pole piece 2 and the diaphragm 3 are fixed on the winding needle, that is, the starting ends of the first pole piece 1 and the second pole piece 2 are located at the winding center. As the winding needle rotates, the first pole The sheet 1 and the second pole piece 2 are rolled to form a structure with inner and outer layers; when the winding is completed, the pole piece is cut off by a knife or laser at the end of the winding to form the end of the battery pole piece.

The wound electrode assembly formed after winding is shown in FIG. 4 , which shows the winding state of the first pole piece 1 , the second pole piece 2 and the separator 3 in the wound electrode assembly. The first pole piece 1 and the second pole piece 2 in the rolled electrode assembly in this application are separated by a separator 3. The first pole piece 1, the second pole piece 2 and the separator 3 are rolled along the winding direction X. The winding structure 14 is formed.

According to some embodiments of the present application, please refer to FIGS. 4 to 7 together. The present application provides an electrode assembly 13. The electrode assembly 13 includes a winding structure 14 and an insulator 4. The winding structure 14 includes a first pole piece 1, a diaphragm 3 and a second pole piece 2. The first pole piece 1 and the second pole piece The pole piece 2 is separated by the diaphragm 3. The first pole piece 1, the diaphragm 3 and the second pole piece 2 are wound along the winding direction X. The first pole piece 1 includes a first current collector 101 and a first current collector 101. Insulating member 4 is connected to the first active material layer 102 of 101 and the first pole piece 1. The insulating member 4 covers the end surface of the first current collector 101 in the winding direction X, so that the first pole piece 1 and the second pole piece 2 insulation settings.

In this embodiment, the first pole piece 1 may be a cathode pole piece, the corresponding first active material layer 102 may be a cathode active material layer, and the second pole piece 2 may be an anode pole piece.

For the first pole piece 1, the first active material layer 102 is usually laminated and covered on both sides of the first current collector 101 to form the first pole piece 1. The first current collector 101 can be made of a metal aluminum substrate. .

An insulating member 4 is provided on the first pole piece 1 , and the insulating member 4 covers at least two end surfaces of the first current collector 101 . Alternatively, the insulating member 4 can be provided on only one end surface, or on both ends. An insulating member 4 is provided on both end surfaces at the same time.

Optionally, the insulating member 4 can be attached to the end surface of the first current collector 101 , or can be spaced apart from the end surface of the first current collector 101 , so as to completely cover the end surface.

In order to avoid electrical contact between the first pole piece 1 and the second pole piece 2, the insulating member 4 can be made of insulating tape. The specific material of the insulating member 4 is not specifically limited in this application.

An electrode assembly 13 according to the embodiment of the present application is provided with an insulating member 4 on the end surface of the first pole piece 1 and the insulating member 4 covers the first current collector 101 of the first pole piece 1 so that the first current collector 101 Insulated from the outside world, the end face protection of the first pole piece 1 is formed, preventing the first pole piece 1 and the second pole piece 2 from overlapping at the end face after the diaphragm 3 is punctured, and avoiding the end face of the first current collector 101 The risk of short circuit caused by electrical connection with the outside world improves the safety performance of the electrode assembly 13 during operation.

According to some embodiments of the present application, please continue to refer to Figure 7. The insulating member 4 includes a side plate 401. The side plate 401 is connected to the first pole piece 1 and covers the end surface.

In this embodiment, the structure of the insulating member 4 includes a side plate 401. The insulating member 4 specifically covers the end surface of the first current collector 101 through the side plate 401. Therefore, the specific size of the side plate 401 is determined by the end surface. The size is determined to meet the complete coverage of the end face.

In the electrode assembly 13 of the embodiment of the present application, the insulating member 4 is connected through the side plate 401 and covers the end surface of the first current collector 101, which provides a feasible structure of the insulating member 4. The side plate 401 can be connected with the electrode assembly 13. The end surface contours of the first current collector 101 are coupled to facilitate connection while ensuring coverage of the end surface of the first current collector 101 .

According to some embodiments of the present application, please continue to refer to Figure 7. In the thickness direction Y of the first pole piece 1 , the extension length of the side plate 401 is greater than the sum of the thickness of the first current collector 101 and the thickness of the first active material layer 102 .

Since the first active material layers 102 are respectively stacked on both sides of the first current collector 101, in consideration of completely covering the end surface of the first current collector 101 and saving plate materials, the side plates 401 can be extended in the thickness direction Y. The length is exactly equal to the thickness of the first current collector 101 .

On the premise that the end surface of the first current collector 101 is completely covered by the side plate 401 , the extension length of the side plate 401 in the thickness direction Y can be set arbitrarily, and can extend to any position on the first active material layer 102 .

In order to improve the stability of the connection, the extension length of the side plate 401 in the thickness direction Y can be increased to provide a larger coverage area. Optionally, the extension length of the side plate 401 is equal to or greater than the first current collector 101 The sum of the thickness of the side plate 401 and the thickness of the first active material layer 102 is generally less than or equal to 5 mm.

An electrode assembly 13 in the embodiment of the present application limits the extension length of the side plate 401 so that the side plate 401 covers the first current collector 101 and the first active material layer 102 at the same time, thereby ensuring that the side plate 401 can The thickness direction Y of the pole piece 1 completely covers the end surface of the first current collector 101, which avoids the exposure of partial end surfaces and improves the reliability of insulation protection.

According to some embodiments of the present application, please continue to refer to Figure 7. The insulating member 4 includes two end plates 402 oppositely arranged in the thickness direction Y. The two end plates 402 are connected to and enclosed by the side plates 401 to form a frame structure. The side plates 401 cover the end surface and the first active material layer 102, along the In the thickness direction Y, the orthographic projection of the end plate 402 covers part of the first active material layer 102 .

The prerequisite for setting up the two end plates 402 is to ensure that the extension length of the side plate 401 is greater than the sum of the thickness of the first current collector 101 and the thickness of the first active material layer 102, thereby providing a certain limit for the arrangement of the two end plates 402. Space.

Optionally, the two end plates 402 can extend in the winding direction

The two end plates 402 can be attached to the first active material layer 102 and extended. It can be understood that the longer the extension length of the two end plates 402 is, the larger the coverage area will be and the higher the stability of the connection will be, and vice versa. Low.

An electrode assembly 13 in the embodiment of the present application forms a frame structure by arranging two end plates 402 in the insulating member 4 and connecting them to the side plates 401 respectively. While the side plates 401 can completely cover the end surface, the two end plates 402 are connected to the side plates 401. The end plate 402 covering part of the first active material layer 102 will increase the overall connection strength of the insulating member 4 , improve the stability of the connection, and reduce the risk of the insulating member 4 falling off.

As an optional embodiment, the side plate 401 is a flat plate structure, and the two end plates 402 are vertically connected to the side plate 401 and enclosed to form a frame structure. The insulating member 4 is connected to the end surface and the first active material layer through the side plate 401 102 connections.

Considering that the end face is usually flat, the side plate 401 is set as a flat plate structure to adapt to the end face and facilitate connection.

When the two end plates 402 are vertically connected to the side plates 401 respectively, a right angle is formed between the end plates 402 and the side plates 401, and the insulating member 4 forms a C-shaped frame structure as a whole, and the end faces are covered and connected through three faces, where The flat structure of the side plate 401 can be attached to the end face connection to achieve coverage.

An electrode assembly 13 in the embodiment of the present application provides a solution in which the side plate 401 is a flat plate structure. By setting the side plate 401 to a flat plate structure and vertically connecting it to the two end plates 402, the side plate 401 can be closely connected The end face arrangement of the first current collector 101 improves the stability of the insulation and is more in line with the contour design of conventional pole pieces.

As an optional embodiment, please refer to Figure 8. The side plate 401 has a tapered plate structure. The side plate 401 includes a first side part 4a and a second side part 4b. The first side part 4a and the second side part 4b. One end is connected to the two end plates 402 respectively and the other end is arranged to intersect, so that the insulating member 4 forms a tapered frame structure.

Generally, the distance between the intersection of the first side part 4a and the second side part 4b and the end surface is greater than or equal to 5 microns and does not exceed the distance between the first pole piece 1 and the second pole piece 2 in the winding direction X. The purpose is to On the premise of covering the end surface, avoid affecting the feeding position of the pole piece.

It can be understood that the first side portion 4a and the second side portion 4b can be understood as side plates 401 extending at a certain angle, and the two are intersected and spliced to form a tapered plate structure of the side plate 401.

The first side part 4a and the second side part 4b are arranged to intersect, and their extension angles may be the same or different, as long as the projection of the first side part 4a and the second side part 4b in the winding direction X covers the end surface, Alternatively, when the extension angles of the two are the same, they can be symmetrically distributed along the winding direction X with the first current collector 101 as the center.

Since the first side portion 4a and the second side portion 4b are arranged to intersect, the tapered structure of the side plate 401 forms a hollow portion, so that the side plate 401 is spaced apart from the end surface and can also cover the end surface.

An electrode assembly 13 in the embodiment of the present application provides a solution in which the side plate 401 has another tapered structure. The side plate 401 is divided into a first side part 4a and a second side part 4b, so that they are connected with the first side part 4a. The end faces of the current collector 101 are arranged at a certain distance, which can also insulate the end faces from the outside world, improve safety performance, and reflect the diversity of the structure.

According to some embodiments of the present application, please refer to FIG. 8 and FIG. 9 together. Along the winding direction X, the extension length of the two end plates 402 is greater than or equal to 0.3 mm and less than or equal to 50 mm.

It can be understood that when the extension length of the end plate 402 is longer, the overall connection strength of the insulating member 4 is higher and the connection is more stable. However, when the extension length of the end plate 402 is too long, it will cover a larger area. The first active material layer 102 affects its normal deintercalation of lithium, resulting in low energy density.

The electrode assembly 13 in the embodiment of the present application limits the extension length of the two end plates 402 so that the entire insulating member 4 can not only meet the requirements for connection stability, but also ensure that the pole piece is at normal energy density.

As an optional embodiment, in the winding direction X, the absolute value of the difference in extension length of the two end plates 402 is greater than zero.

The electrode assembly 13 of the embodiment of the present application can make the extension lengths of the two end plates 402 unequal during production and processing, which improves the flexibility of the production process and also increases the diversity of the structure of the insulating member 4 to meet more connection needs.

According to some embodiments of the present application, please refer to Figures 10 to 12 together. The insulation member 4 includes two top plates 403 oppositely arranged in the axial direction Z of the winding structure 14. The two top plates 403 are connected to the two end plates 402 and the side plates 401 respectively and enclose to form a box structure. Along the winding structure In the axial direction Z of 14, the orthographic projection of the top plate 403 covers at least part of the first active material layer 102.

In this embodiment, two top plates 403 are added on the basis of the two end plates 402 and the side plates 401. The two top plates 403 are oppositely arranged in the axial direction Z and together form a box structure. The top plate 403 is orthogonally projected. At least part of the first active material layer 102 is covered to form a stable connection in the axial direction Z.

An electrode assembly 13 in the embodiment of the present application, by setting two top plates 403 opposite in the axial direction Z, the insulating member 4 forms a box structure as a whole. While ensuring that the insulating member 4 covers the end surface, the two additional top plates 403 This further improves the stability of the connection of the insulating component 4 and reduces the risk of it falling off.

As an optional embodiment, as shown in Figure 11, the top plate 403 has a flat plate structure. The top plate 403 is vertically connected to the end plate 402 and the side plate 401 respectively to form a box structure. The top plate 403 is connected to the first active material layer. 102 top fit setting.

Optionally, the top plate 403 is provided in a flat plate shape and extends in the winding direction The extension length of the top plate 403 is not particularly limited.

Optionally, the top plate 403 is vertically connected to the end plate 402 and the side plate 401 in pairs, forming right angles to each other, and the insulating member 4 as a whole forms a rectangular box structure.

An electrode assembly 13 in the embodiment of the present application provides a specific structural form of the box structure. By arranging the top plate 403 into a flat plate structure and attached to the top surface of the first active material layer 102, the original insulating member is 4 is added to five-face connections through three-face connections, further improving the stability of the overall connection of the insulator 4.

As an optional embodiment, as shown in Figure 12, the top plate 403 has a tapered plate structure. The top plate 403 includes a first top 4c and a second top 4d. One end of the first top 4c and the second top 4d is connected to the end respectively. The plates 402 are connected and the other ends extend close to each other and intersect in the axial direction Z of the winding structure 14 , and the top plate 403 is spaced apart from the top surface of the first active material layer 102 .

It can be understood that the first top 4c and the second top 4d can be understood as a top plate 403 extending obliquely at a certain angle along the axial direction Z. The two are intersected and spliced to form a conical plate structure of the top plate 403.

The first top 4c and the second top 4d are arranged to intersect, and their extension angles may be the same or different. The projections of the first top 4c and the second top 4d in the axial direction Z cover part of the top surface of the first pole piece 1, Alternatively, when the extension angles of the two are the same, they can be symmetrically distributed along the axial direction Z with the first current collector 101 as the center.

Since the first top 4c and the second top 4d are intersectingly arranged, the tapered structure of the top plate 403 forms a hollow portion, so that the top plate 403 is spaced apart from the top surface of the first pole piece 1 and covers part of the top surface of the first pole piece 1 .

An electrode assembly 13 in the embodiment of the present application provides another specific structural form of the box structure. By arranging the first top 4c and the second top 4d, the top plate 403 of the insulating member 4 is connected with the first active material layer 102 The spacing of the top surfaces not only ensures that the side plates 401 cover the end surfaces, but also improves the stability of the connection in the axial direction Z.

According to some embodiments of the present application, please refer to Figure 13. The side plate 401 has a flat structure, and the two end plates 402 are vertically connected to the side plate 401 and enclosed to form a frame structure. The insulating member 4 is connected to the end surface through the side plate 401. Along the winding direction X, the end plate 402 is connected to the first active The material layers 102 are arranged one after another, and in the thickness direction Y, the end plate 402 is flush with the surface of the first active material layer 102 facing away from the first current collector 101 .

In this embodiment, the two end plates 402 of the insulating member 4 and the first active material layer 102 are arranged on the same layer and flush, so that the two end plates 402 and the first active material layer 102 have the same thickness.

Optionally, the extension lengths of the two end plates 402 in the winding direction Can.

The structure of the insulating member 4 in this embodiment can be understood as covering the end surface and part of the side surfaces of the first current collector 101 with the side plate 401 and the two end plates 402. This not only forms insulation protection for the end surface, but also maintains the The flatness of the overall structure of the first pole piece 1.

In the electrode assembly 13 of the embodiment of the present application, the insulating member 4 and the first active material layer 102 are arranged flush with each other. The structure formed makes the electrode piece free of protrusions or step structures, the surface is smoother, and the overall force is more uniform. Easy to wind and assemble.

According to some embodiments of the present application, please refer to Figure 14. The first current collector 101 has two end surfaces in the winding direction X, and the insulating member 4 is provided on both end surfaces of the first current collector 101 .

Since the first current collector 101 has two end surfaces in the winding direction

In the electrode assembly 13 of the embodiment of the present application, the insulating members 4 can be disposed on the two end surfaces of the first current collector 101 in the winding direction External influences further provide guarantee for the safety performance of the pole piece.

As an optional embodiment, the insulating member 4 is integrally formed.

In this embodiment, the insulating member 4 can be integrally formed through processing technology. Of course, the insulating member 4 can also be formed by splicing the side plates 401 , the end plates 402 and the top plate 403 .

In terms of processing technology, the electrode assembly 13 of the embodiment of the present application can make the insulating member 4 integrally formed, which simplifies the process steps, improves the production efficiency, and saves the manufacturing cost.

According to some embodiments of the present application, the present application also provides a battery cell 40 including the electrode assembly 13 described in any of the above solutions.

According to some embodiments of the present application, the present application also provides a battery 100 including the battery cell 40 as described above.

According to some embodiments of the present application, the present application also provides an electrical device, including the battery 100 as described above, and the battery 100 is used to provide electrical energy to the electrical device.

The power-consuming device may be any of the aforementioned devices or systems using the battery 100 .

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present application. The scope shall be covered by the claims and description of this application. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any way. The application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims (20)

1. An electrode assembly, including:

   The winding structure includes a first pole piece, a diaphragm, and a second pole piece. The first pole piece and the second pole piece are separated by the diaphragm. The first pole piece, the diaphragm, and the second pole piece Wound and arranged along the winding direction, the first pole piece has an end in the winding direction;

   Insulating member, the insulating member is connected to the first pole piece, and the insulating member covers the end of the first pole piece and is arranged so that the first pole piece and the second pole piece Insulation settings.
2. The electrode assembly according to claim 1, wherein the first pole piece includes a first current collector and a first active material layer disposed on both sides of the first current collector, and the end portion includes the first current collector. The end surface of the current collector in the winding direction, the insulating member at least partially covers the end surface.
3. The electrode assembly of claim 2, wherein the insulating member is disposed covering the end surface and at least part of the first active material layer.
4. The electrode assembly according to claim 2, wherein the insulating member includes a side plate connected to the first pole piece and covering the end surface.
5. The electrode assembly according to claim 4, wherein in the thickness direction of the first pole piece, the extension length of the side plate is greater than the thickness of the first current collector and the thickness of the first active material layer. and.
6. The electrode assembly according to claim 5, wherein the insulating member includes two end plates arranged oppositely in the thickness direction, and the two end plates are connected to the side plates and enclosed to form a frame structure. , the side plate covers the end surface and the first active material layer, and along the thickness direction, the orthographic projection of the end plate covers part of the first active material layer.
7. The electrode assembly according to claim 6, wherein the side plates are flat plates, two end plates are vertically connected to the side plates and enclosed to form a frame structure, and the insulating member passes through the side plates. Connected to the end surface and the first active material layer.
8. The electrode assembly according to claim 6, wherein the side plate is a tapered plate structure, the side plate includes a first side part and a second side part, one ends of the first side part and the second side part The two end plates are respectively connected to each other and the other end is arranged to intersect, so that the insulating member forms a tapered frame structure.
9. The electrode assembly according to claim 6, wherein the extension length of the two end plates is greater than or equal to 0.3 mm and less than or equal to 50 mm along the winding direction.
10. The electrode assembly according to claim 9, wherein the extension length of the two end plates along the winding direction does not exceed 10 mm.
11. The electrode assembly according to claim 6, wherein the absolute value of the difference in extension lengths of the two end plates in the winding direction is greater than zero.
12. The electrode assembly according to claim 6, wherein the insulating member includes two top plates oppositely arranged in the axial direction of the winding structure, and the two top plates are respectively connected with the two end plates and the The side plates are connected and enclosed to form a box structure, and the top plate covers at least part of the first active material layer in orthographic projection along the axial direction of the winding structure.
13. The electrode assembly according to claim 12, wherein the top plate is a flat plate structure, the top plate is vertically connected to the end plate and the side plate respectively and enclosed to form a box structure, and the top plate and the third A top surface of an active material layer is attached and disposed.
14. The electrode assembly according to claim 12, wherein the top plate is a tapered plate structure, the top plate includes a first top and a second top, one ends of the first top and the second top are respectively connected with the end plate. The other ends are connected and extend close to each other in the axial direction of the winding structure and are arranged to intersect, and the top plate is spaced apart from the top surface of the first active material layer.
15. The electrode assembly according to claim 6, wherein the side plates are flat plates, two end plates are vertically connected to the side plates and enclosed to form a frame structure, and the insulating member passes through the side plates. Connected to the end surface, along the winding direction, the end plate and the first active material layer are arranged successively, and in the thickness direction, the end plate and the first active material layer are away from the The surface of the first current collector is flush.
16. The electrode assembly according to claim 1, wherein the first pole piece has two end portions in the winding direction, and the insulating member is provided on the two end portions of the first pole piece. Ends.
17. The electrode assembly according to any one of claims 1 to 16, wherein the insulating member is integrally formed.
18. A battery cell, comprising the electrode assembly according to any one of claims 1 to 17.
19. A battery, comprising the battery cell according to claim 18.
20. An electrical device, comprising the battery according to claim 19.

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