CN221239646U - Electrode assembly, battery cell, battery and electric equipment - Google Patents

Abstract

The application discloses an electrode assembly, a battery monomer, a battery and electric equipment, wherein the electrode assembly comprises a first pole piece, a second pole piece, a first diaphragm and a second diaphragm, the polarities of the first pole piece and the second pole piece are opposite, the first pole piece, the first diaphragm, the second pole piece and the second diaphragm are sequentially overlapped and wound into a whole, the second diaphragm forms the outer side surface of the electrode assembly, a first colloid is arranged between the tail end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer, and the first colloid is bonded with the tail end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer. Therefore, the first colloid is arranged between the tail end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer, and is bonded with the tail end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer, so that the process of cutting the adhesive tape is omitted in the process of fixing the tail end of the electrode assembly, the winding machine does not need to stop working, and the production efficiency of the electrode assembly is improved.

Description

Electrode assembly, battery cell, battery and electric equipment

Technical Field

The application relates to the technical field of batteries, in particular to an electrode assembly, a battery monomer, a battery and electric equipment.

Background

With the development of the battery industry, the application of batteries is more and more widespread, and the safety problem of the batteries is concerned. In the related art, the battery cell includes an electrode assembly, which may form a winding structure, and in the winding process of the electrode assembly, in order to fix the morphology of the electrode assembly, the electrode assembly may be fixed at the finishing end of the electrode assembly using a sticker after winding. However, during the attachment of the decal, the winder needs to be stopped, which reduces the production efficiency of the electrode assembly.

Disclosure of utility model

The application provides an electrode assembly, a battery monomer, a battery and electric equipment, which can solve the problem of lower production efficiency of the electrode assembly.

The electrode assembly comprises a first pole piece, a second pole piece, a first diaphragm and a second diaphragm, wherein the polarities of the first pole piece and the second pole piece are opposite, the first pole piece, the first diaphragm, the second pole piece and the second diaphragm are sequentially stacked and wound into a whole, the second diaphragm forms the outer side surface of the electrode assembly, a first colloid is arranged between the ending end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer, and the first colloid is bonded with the ending end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer.

In the electrode assembly of the embodiment of the application, the first colloid is arranged between the ending end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer, and the first colloid is bonded with the ending end of the first diaphragm of the outermost layer and the second diaphragm of the secondary outer layer, so that the process of cutting the adhesive tape is omitted in the process of fixing the ending end of the electrode assembly, the winding machine does not need to stop working, and the production efficiency of the electrode assembly is improved.

In some embodiments, the first colloid is disposed symmetrically about a center of the first separator in a width direction. Therefore, the colloid extends from the center to two edges of the first diaphragm in the width direction, so that the bonding force between the first diaphragm and the second diaphragm is more uniform, and the first diaphragm and the second diaphragm are more stably bonded.

In certain embodiments, the ratio of the width of the first gel to the width of the first membrane ranges from 0.75 to 1. Thus, the first colloid is larger in width for bonding the first diaphragm and the second diaphragm, and the first colloid is favorable for stably bonding the first diaphragm and the second diaphragm.

In certain embodiments, the length of the first gel is in the range of 3mm to 20mm along the length of the first membrane. In this way, in the case of the above range, the adhesive force formed by the first colloid can stably adhere the first separator and the second separator.

In certain embodiments, the thickness of the first gel ranges from 0.2mm to 0.4mm. Therefore, under the condition that the adhesive force of the first colloid is enough, the thickness of the first colloid is smaller, so that the structure of the electrode assembly is more compact, the miniaturization of the electrode assembly is facilitated, and the energy density of the battery cell is improved.

In some embodiments, the first colloid is stacked with the first separator, and the first colloid is disposed on at least one side in the thickness direction of the first separator. Therefore, the first colloid and the first diaphragm can be pre-fixed before the first diaphragm is wound, and can be directly bonded with the second diaphragm after the first diaphragm is wound, so that the ending end of the electrode assembly is not required to be fixed by the adhesive tape, and the production efficiency of the electrode assembly is improved.

In some embodiments, the trailing ends of the first separator and the second separator both exceed the trailing end of the first pole piece and exceed the trailing end of the second pole piece in the winding direction of the electrode assembly. Therefore, the first pole piece and the second pole piece can be completely isolated by the diaphragm, and the risk of mutual short circuit of the first pole piece and the second pole piece is reduced.

In certain embodiments, the trailing end of the first membrane and the trailing end of the second membrane are bonded by a second glue. In this way, the trailing end of the first separator and the trailing end of the second separator can be fixed together, so that the electrode assembly forms one body.

In some embodiments, the second colloid is stacked with the second separator, and the second colloid is disposed on at least one side of the second separator in the thickness direction. Therefore, the second colloid and the second diaphragm can be pre-fixed before the second diaphragm is wound, and can be directly bonded with the first diaphragm after the second diaphragm is wound, so that the ending end of the electrode assembly is not required to be fixed by the adhesive tape, and the production efficiency of the electrode assembly is improved.

The battery cell of an embodiment of the present application includes a case and the electrode assembly of any of the above embodiments, the electrode assembly being disposed in the case.

The battery according to the embodiment of the application includes a plurality of the battery cells described in the above embodiment.

The electric equipment provided by the embodiment of the application comprises the battery monomer or the battery of any embodiment.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a powered device according to some embodiments of the present application;

Fig. 2 is a schematic view of a battery according to some embodiments of the present application;

fig. 3 is an exploded view of a battery cell provided in some embodiments of the application;

Fig. 4 is a schematic perspective view of an electrode assembly provided in some embodiments of the present application;

FIG. 5 is a schematic cross-sectional view of the electrode assembly of FIG. 4 along V-V;

FIG. 6 is an enlarged schematic view of a portion of the electrode assembly A of FIG. 5;

FIG. 7 is a schematic illustration of the cooperation of a first membrane with a first gel according to some embodiments of the present application;

FIG. 8 is a schematic plan view of a first membrane and first gel combination according to some embodiments of the application;

FIG. 9 is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the application;

FIG. 10 is a schematic illustration of the cooperation of a first membrane with a first gel according to some embodiments of the present application;

FIG. 11 is a schematic illustration of the first membrane engaging a first gel according to some embodiments of the present application;

FIG. 12 is a schematic illustration of the cooperation of a second membrane with a second gel provided in some embodiments of the application;

FIG. 13 is a schematic illustration of the cooperation of a second membrane with a second gel according to some embodiments of the present application;

Fig. 14 is a schematic diagram illustrating the cooperation between the second membrane and the second colloid according to some embodiments of the present application.

Reference numerals illustrate:

1000-electric equipment, 200-battery, 300-controller, 400-motor, 100-battery cell, 10-casing, 20-electrode assembly, 21-first pole piece, 22-second pole piece, 23-first diaphragm, 24-second diaphragm, 25-first colloid, 26-second colloid.

Detailed Description

Embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present application, and thus are merely examples, and are not intended to limit the scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein 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 such phrases 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 of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

Currently, the more widely the battery is used in view of the development of market situation. The battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and various fields such as aerospace and the like. With the continuous expansion of the battery application field, the market demand thereof is also continuously expanding.

The battery unit comprises an electrode assembly, the electrode assembly comprises a positive electrode plate, a negative electrode plate and a diaphragm, the electrode assembly can be wound into a whole, and after the electrode assembly is wound, the tail end of the electrode assembly is required to be fixed by adopting adhesive paper, so that the shape of the electrode assembly is fixed. However, in order to make the position of the decal attachment accurate during the decal attachment, the winding machine needs to be stopped, so that the production efficiency of the electrode assembly is reduced.

In order to solve the problem that the winding machine needs to stop working in the production process of the electrode assembly to reduce the production efficiency of the electrode assembly, a first colloid is arranged between the ending end of the first diaphragm on the outermost layer and the second diaphragm on the secondary outer layer, and the first colloid is bonded with the ending end of the first diaphragm on the outermost layer and the second diaphragm on the secondary outer layer, so that the process of cutting adhesive tapes is omitted in the process of fixing the ending end of the electrode assembly, the winding machine does not need to stop working, and the production efficiency of the electrode assembly is improved.

It should be noted that, in the present application, the "pole piece" may refer to the first pole piece or the second pole piece. One of the first pole piece and the second pole piece is a positive pole piece, and the other is a negative pole piece. "separator" may refer to a first separator or a second separator.

The electric equipment comprises a battery cell or a battery in any one of the following embodiments. Specifically, the electric equipment can use a battery or a battery monomer as a power supply, and the electric equipment can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

For convenience of description, the following embodiments will take the electric device 1000 according to the embodiment of the present application as an example of a vehicle.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an electric device 1000 according to some embodiments of the application. The battery 200 is provided in the interior of the vehicle, and the battery 200 may be provided at the bottom or the head or the tail of the vehicle. The battery 200 may be used for power supply of a vehicle, for example, the battery 200 may be used as an operating power source of the vehicle.

The vehicle may also include a controller 300 and a motor 400, the controller 300 being configured to control the battery 200 to power the motor 400, for example, for operating power requirements during start-up, navigation, and travel of the vehicle.

In an embodiment of the present application, the battery 200 may be used not only as an operating power source of a vehicle but also as a driving power source of the vehicle to supply driving power to the vehicle instead of or in part of fuel oil or natural gas.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a battery 200 according to some embodiments of the application. The battery 200 according to the embodiment of the present application includes the battery cell 100 according to any one of the following embodiments. In this way, since the electrode assembly can be effectively impregnated in the battery cell and the function of the insulating film is not greatly affected, the battery according to the embodiment of the application has good performance and can continuously and stably operate in a safe environment.

In the embodiment of the present application, the battery cell 100 may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited by the embodiment of the present application. The battery cell 100 may have a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, etc., which are not limited thereto according to the embodiment of the present application. The battery cells 100 are generally divided into three types in a package manner: the cylindrical battery cell, the prismatic battery cell, and the pouch battery cell, to which the embodiment of the present application is not limited.

The battery 200 generally includes a battery case 210 for enclosing one or more battery cells 100. The plurality of batteries can be accommodated in the battery case 210, and the battery case 210 can prevent the liquid or other foreign matters from affecting the charge or discharge of the battery cell 100. The battery case 210 serves as a supporting body of the battery module, and plays a key role in safety work and protection of the battery module. The battery box 210 meets the strength and rigidity requirements and the protection level requirements of the electrical equipment housing, while providing collision protection. The battery case 210 may have a rectangular parallelepiped shape, a square shape, or the like. The battery case 210 may be cast from a steel plate, an aluminum alloy, or the like; novel lightweight materials, such as glass fiber reinforced composites, carbon fiber reinforced composites, and the like, may also be used.

Referring to fig. 3, fig. 3 is a disassembled view of a battery cell 100 according to some embodiments of the application. In some embodiments, the battery cell 100 includes a case 10 and an electrode assembly 20, the electrode assembly 20 being disposed in the case 10.

The electrode assembly 20 is a component in which electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 20 may be contained within the case 10 of the battery cell 100.

Referring to fig. 4-6, fig. 4 is a schematic perspective view of an electrode assembly 20 according to some embodiments of the present application. Fig. 5 is a schematic cross-sectional view of the electrode assembly 20 of fig. 4 along V-V. Fig. 6 is an enlarged schematic view of a portion of the electrode assembly a of fig. 5. The electrode assembly 20 of the embodiment of the application comprises a first pole piece 21, a second pole piece 22, a first diaphragm 23 and a second diaphragm 24, wherein the polarities of the first pole piece 21 and the second pole piece 22 are opposite, the first pole piece 21, the first diaphragm 23, the second pole piece 22 and the second diaphragm 24 are sequentially stacked and wound into a whole, the second diaphragm 24 forms the outer side surface of the electrode assembly 20, a first colloid 25 is arranged between the tail end of the first diaphragm 23 of the outermost layer and the second diaphragm 24 of the secondary outer layer, and the first colloid 25 is bonded with the tail end of the first diaphragm 23 of the outermost layer and the second diaphragm 24 of the secondary outer layer.

Specifically, the first pole piece 21 and the second pole piece 22 are two pole pieces of opposite polarities. The positive electrode active material and the negative electrode active material may react with the electrolyte during charge and discharge of the battery cell 100.

The first diaphragm 23 and the second diaphragm 24 jointly isolate the first pole piece 21 and the second pole piece 22, and in the embodiment of the application, the first diaphragm 23 is arranged between the first pole piece 21 and the second pole piece 22, and the first pole piece 21 and the second pole piece 22 are mutually spaced and do not contact, so that the risk of short circuit of the first pole piece 21 and the second pole piece 22 is reduced.

The first pole piece 21, the second pole piece 22, the first separator 23, and the second separator 24 are stacked on each other in the respective thickness directions. The electrode assembly 20 may be wound in a cylindrical shape or may be wound in a substantially square shape.

In the embodiment of the present application, the second separator 24 is positioned at the outermost layer of the electrode assembly 20 after the electrode assembly 20 is wound, and thus, the second separator 24 may form the outer side of the electrode assembly 20.

The outermost first separator 23 refers to a first separator 23 in which a layer of the first separator 23 farthest from the winding center of the electrode assembly 20 is the outermost layer in a section of the electrode assembly 20 taken in a plane parallel to the thickness direction of the first separator 23 and perpendicular to the width direction of the first separator 23.

The second separator 24 of the secondary outer layer refers to a second separator 24 of the secondary outer layer, in which one layer of the second separator 24, which is the second farthest from the winding center of the electrode assembly 20, is the second separator 24 of the secondary outer layer in a section taken through the electrode assembly 20 in a plane parallel to the thickness direction of the second separator 24 and perpendicular to the width direction of the second separator 24.

Specifically, the first colloid 25 is, for example, a double-sided tape, a tape formed after curing a liquid, or the like. The first colloid 25 may be made of epoxy resin, phenolic resin, urea-formaldehyde resin, polyurethane, etc. It should be noted that the first gel 25 may have a certain elasticity, so that the first gel 25 does not damage the first membrane 23 and the second membrane 24.

In one example, the first paste 25 may be disposed at the end of the first separator 23 of the outermost layer during the production of the electrode assembly 20, and the first paste 25 may adhere the end of the first separator 23 of the outermost layer and the second separator 24 of the sub-outer layer when the electrode assembly 20 is wound and terminated.

In another example, the first paste 25 may be disposed on the second separator 24 of the outer layer during the production of the electrode assembly 20, and the first paste 25 may adhere the ending end of the first separator 23 of the outermost layer and the second separator 24 of the sub-outer layer when the electrode assembly 20 is wound to end.

Referring to fig. 7, in still another example, the first paste 25 may be disposed on the second separator 24 of the outer layer and the end of the first separator 23 of the outermost layer during the production of the electrode assembly 20, and the first paste 25 may adhere the end of the first separator 23 of the outermost layer and the second separator 24 of the sub-outer layer when the electrode assembly 20 is wound and terminated.

Therefore, the first colloid 25 is disposed between the tail end of the first separator 23 of the outermost layer and the second separator 24 of the secondary outer layer, and the first colloid 25 adheres to the tail end of the first separator 23 of the outermost layer and the second separator 24 of the secondary outer layer, so that the process of cutting the adhesive tape is omitted in the process of fixing the tail end of the electrode assembly 20, the winding machine does not need to stop working, and the production efficiency of the electrode assembly 20 is improved.

In some embodiments, the adhesive force of the first glue 25 to the trailing end of the first membrane 23 of the outermost layer and the second membrane 24 of the secondary outer layer may be greater than 5N, such that the adhesive force of the first glue 25 is sufficient, and the first membrane 23 and the second membrane 24 do not come loose.

Referring to fig. 8, fig. 8 is a schematic plan view illustrating a combination of a first membrane 23 and a first colloid 25 according to some embodiments of the present application. In some embodiments, the first colloid 25 is disposed symmetrically about the center of the first separator 23 in the width direction.

The width direction of the first diaphragm 23 is a direction perpendicular to the thickness direction of the first diaphragm 23, and the length direction of the first diaphragm 23 is perpendicular to the width direction of the first diaphragm 23. Generally, the electrode assembly 20 is wound in the length direction of the first separator 23. Accordingly, the width of the first separator 23 is in an expanded state at the beginning or ending of the winding of the electrode assembly 20.

In this way, the first glue 25 extends from the center of the width direction of the first membrane 23 to both edges, so that the adhesion force between the first membrane 23 and the second membrane 24 is more uniform, which is beneficial to more stably adhering the first membrane 23 and the second membrane 24.

It should be noted that, on the same surface of the first separator 23, the first colloid 25 may extend continuously along the width direction of the first separator 23, or may be intermittently distributed along the width direction of the first separator 23.

Of course, in other embodiments, the first glue 25 may glue the long edges of the pole pieces of the first membrane 23 and the long edges of the second membrane 24.

In certain embodiments, the ratio of the width W1 of the first gel 25 to the width W2 of the first membrane 23 ranges from 0.75 to 1. For example, the ratio W1/W2 may be 0.75, 0.78, 0.8, 0.9 or 1.

In this way, the width of the first adhesive 25 to bond the first and second diaphragms 23 and 24 is large, which is advantageous for the first adhesive 25 to bond the first and second diaphragms 23 and 24 stably.

Referring to fig. 6, in some embodiments, the length of the first gel 25 along the length of the first membrane 23 ranges from 3mm to 20mm. For example, the length L1 of the first gel 25 may be 3mm, 5mm, 10mm, 15mm, 20mm, or the like. As discussed above, the first separator 23 is wound along its own length direction, and thus, if the first colloid 25 is wound in a curved state, the length of the first colloid 25 is the size in a flattened state.

In this way, when the length L1 of the first colloid 25 is within the above range, the adhesive force formed by the first colloid 25 can stably adhere the first separator 23 and the second separator 24.

Referring to fig. 6, in some embodiments, the thickness of the first gel 25 ranges from 0.2mm to 0.4mm. For example, the thickness H1 of the first gel 25 may be 0.2mm, 0.26mm, 0.3mm, 0.35mm, 0.4mm, etc. in size. In this way, in the case that the adhesive force of the first gel 25 is sufficient, the thickness of the first gel 25 is smaller, so that the structure of the electrode assembly 20 is more compact, which is beneficial to miniaturization of the electrode assembly 20 and improvement of the energy density of the battery cell 100. In addition, the thickness of the first gel 25 has a small influence on the degree of deformation of the first separator 23, so that the electrode assembly 20 can be used normally.

Referring to fig. 9, in some embodiments, a first colloid 25 is stacked with a first diaphragm 23, and the first colloid 25 is disposed on at least one side of the first diaphragm 23 in the thickness direction.

Specifically, the area of the first colloid 25 may be equal to the area of the first diaphragm 23, and the edge of the first colloid 25 is aligned with the edge of the first diaphragm 23. In this embodiment, the first colloid 25 may make the adhesive force between the first and second diaphragms 23 and 24 greater than 2N.

Illustratively, the first colloid 25 may be disposed on the first separator 23 before the first separator 23 is wound, and in the process of winding the first separator 23, the first colloid 25 may directly fix the tail end of the first separator 23, so that the winding machine does not need to stop working, thereby improving the production efficiency of the electrode assembly 20.

Referring to fig. 10, in one example, a first gel 25 is provided toward an inner surface of the electrode assembly 20 in a thickness direction of the first separator 23. Referring to fig. 11, in another example, the first colloid 25 is disposed on both surfaces of the first diaphragm 23 in the thickness direction.

In this way, the first colloid 25 and the first separator 23 may be pre-fixed before the first separator 23 is wound, and may be directly bonded with the second separator 24 after the first separator 23 is wound, without fixing the tail end of the electrode assembly 20 with an adhesive tape, which is advantageous for improving the production efficiency of the electrode assembly 20.

Referring again to fig. 5 and 6, in some embodiments, the trailing ends of the first separator 23 and the second separator 24 both extend beyond the trailing end of the first pole piece 21 and beyond the trailing end of the second pole piece 22 in the winding direction of the electrode assembly 20. Alternatively, the first and second diaphragms 23 and 24 are each longer than the length of the first pole piece 21 and longer than the length of the second pole piece 22.

In this way, the first pole piece 21 and the second pole piece 22 can be completely covered, the first pole piece 21 and the second pole piece 22 are completely isolated by the diaphragm, and the risk of shorting the first pole piece 21 and the second pole piece 22 to each other is reduced.

Referring again to fig. 5 and 6, in some embodiments, the trailing end of the first membrane 23 and the trailing end of the second membrane 24 are bonded by the second glue 26.

Specifically, the second colloid 26 is, for example, a double-sided adhesive, a glue formed after curing a liquid, or the like. The second colloid 26 may be made of epoxy resin, phenolic resin, urea-formaldehyde resin, polyurethane, etc. It should be noted that the second gel 26 may have a certain elasticity, so that the second gel 26 does not damage the first membrane 23 and the second membrane 24.

In this way, the trailing end of the first separator 23 and the trailing end of the second separator 24 can be fixed together, so that the electrode assembly 20 forms one body.

In some embodiments, the second gel 26 is disposed symmetrically about the center of the width direction of the second membrane 24.

In this way, the second glue 26 extends from the center of the width direction of the second membrane 24 to two edges, so that the adhesion force between the ending end of the first membrane 23 and the ending end of the second membrane 24 is more uniform, which is beneficial to more stably adhering the first membrane 23 and the second membrane 24.

It should be noted that, on the same surface of the second separator 24, the second colloid 26 may extend continuously along the width direction of the first separator 23, or may be intermittently distributed along the width direction of the first separator 23.

Of course, in other embodiments, the second glue 26 may glue the long edge of the first membrane 23 and the long edge of the second membrane 24.

Referring to fig. 12, in some embodiments, the ratio of the width W3 of the second gel 26 to the width W4 of the second membrane 24 is in the range of 0.75-1. For example, the ratio W3/W4 may be 0.75, 0.78, 0.8, 0.9 or 1. In this way, the width of the second colloid 26 to bond the first and second diaphragms 23 and 24 is large, which is advantageous for the second colloid 26 to stably bond the first and second diaphragms 23 and 24.

Referring to fig. 6, in some embodiments, the length of the second gel 26 along the length of the second membrane 24 ranges from 3mm to 20mm. For example, the length L2 of the second gel 26 may be 3mm, 5mm, 10mm, 15mm, 20mm, etc. in size. As discussed above, the first separator 23 is wound along its own length direction, and thus, if the second colloid 26 is wound in a curved state, the length of the second colloid 26 is a dimension in a flattened state.

In this way, when the length L2 of the second colloid 26 is within the above range, the adhesive force formed by the second colloid 26 can stably adhere the first separator 23 and the second separator 24.

Referring to fig. 6, in some embodiments, the thickness of the second gel 26 ranges from 0.2mm to 0.4mm. For example, the thickness H2 of the second gel 26 may be 0.2mm, 0.26mm, 0.3mm, 0.35mm, 0.4mm, etc. in size. In this way, when the adhesion force of the second colloid 26 is sufficient, the thickness of the second colloid 26 is smaller, so that the structure of the electrode assembly 20 is more compact, which is beneficial to miniaturizing the electrode assembly 20 and improving the energy density of the battery cell 100. In addition, the thickness of the second gel 26 has a small influence on the degree of deformation of the first separator 23, so that the electrode assembly 20 can be used normally.

Referring again to fig. 9, in some embodiments, the second gel 26 is stacked with the second membrane 24, and the second gel 26 is disposed on at least one side of the thickness direction of the second membrane 24.

Specifically, the area of the second gel 26 may be equal to the area of the second membrane 24, and the edge of the second gel 26 is aligned with the edge of the second membrane 24. In such an embodiment, the second gel 26 may cause the adhesive force between the second membrane 24 and the second membrane 24 to be greater than 2N.

Illustratively, the second colloid 26 may be disposed on the second separator 24 before the second separator 24 is wound, and during the winding process of the second separator 24, the second colloid 26 may directly fix the tail end of the second separator 24, so that the winding machine does not need to stop working, thereby improving the production efficiency of the electrode assembly 20.

Referring to fig. 13, in one example, a second separator 24 is provided with a second gel 26 toward an inner surface of the electrode assembly 20 in a thickness direction. Referring to fig. 14, in another example, the second colloid 26 is disposed on both surfaces of the second diaphragm 24 in the thickness direction.

In this way, the second colloid 26 and the second separator 24 may be pre-fixed before the second separator 24 is wound, and may be directly adhered to the first separator 23 after the second separator 24 is wound, without fixing the tail end of the electrode assembly 20 with an adhesive tape, which is advantageous for improving the production efficiency of the electrode assembly 20.

In some embodiments, the region of the first membrane 23 and/or the second membrane 24 provided with the gel may have a permeability greater than 300s/100cc or a completely impermeable state. A gas permeation of greater than 300s/100cc refers to a time of greater than 300 seconds per unit volume of gas permeation through the membrane.

In the description of the present specification, reference to the terms "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the application, the scope of which is defined by the claims and their equivalents.

Claims (12)

1. The utility model provides an electrode assembly, its characterized in that includes first pole piece, second pole piece, first diaphragm and second diaphragm, first pole piece with the polarity of second pole piece is opposite, first pole piece first diaphragm, second pole piece with the second diaphragm stacks gradually and sets up and winds and form integratively, the second diaphragm forms electrode assembly's lateral surface, outermost first diaphragm's ending end with be provided with first colloid between the second diaphragm of secondary outer, first colloid bonds outermost first diaphragm's ending end with secondary outer second diaphragm.

2. The electrode assembly according to claim 1, wherein the first colloid is disposed symmetrically about a center of the first separator in a width direction.

3. The electrode assembly of claim 2, wherein the ratio of the width of the first gel to the width of the first separator ranges from 0.75 to 1.

4. The electrode assembly of claim 1, wherein the length of the first gel along the length of the first separator ranges from 3mm to 20mm.

5. The electrode assembly of claim 1, wherein the thickness of the first gel ranges from 0.2mm to 0.4mm.

6. The electrode assembly according to claim 1, wherein the first gel is provided in a layered arrangement with the first separator, the first gel being provided on at least one side in a thickness direction of the first separator.

7. The electrode assembly of claim 1, wherein the trailing ends of the first separator and the second separator both exceed the trailing end of the first pole piece and exceed the trailing end of the second pole piece in a winding direction of the electrode assembly.

8. The electrode assembly of claim 7, wherein the trailing end of the first separator and the trailing end of the second separator are bonded by a second glue.

9. The electrode assembly according to claim 8, wherein the second gel is provided in a layered arrangement with the second separator, the second gel being provided on at least one side in a thickness direction of the second separator.

10. A battery cell, comprising:

A housing;

The electrode assembly of any one of claims 1-9 disposed in the housing.

11. A battery comprising a plurality of cells according to claim 10.

12. A powered device comprising the battery cell of claim 10 or the battery of claim 11.