Electrode assembly of a battery cell and battery cell

Abstract

This utility model discloses an electrode assembly for a battery cell and a battery cell. The electrode assembly, relating to the field of batteries, includes: a first electrode, a separator, and a second electrode. The first electrode, separator, and second electrode are wound to form an electrode body with a winding hole, the winding hole penetrating the electrode body along a first direction. A support portion is located within the winding hole and extends along the first direction. The support portion defines an assembly hole for a winding needle to insert into, and the support portion forms a through-hole communicating with the assembly hole. A portion of the separator is located within the assembly hole, and the separator passes through the through-hole. Thus, by providing the support portion, the electrode body can be supported. After the electrode expands, the amount of the electrode body collapsing into the winding hole is reduced, thereby reducing the risk of electrode breakage, effectively solving the problem of rapid capacity reduction in the battery cell, which is beneficial for extending the service life of the battery cell and improving its reliability.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to an electrode assembly for a battery cell and a battery cell having the electrode assembly. Background Technology

[0002] In related technologies, lithium-ion battery cells are becoming increasingly indispensable in people's lives, bringing great convenience. Battery cells can be categorized by shape into prismatic, cylindrical, and other irregularly shaped cells. A battery cell includes an electrode assembly, which comprises a first electrode, a separator, and a second electrode. Typically, the separator, first electrode, separator, and second electrode are wound together using a needle winding mechanism to form the electrode assembly. After winding, the needle is withdrawn, creating a hollow space in the center of the assembly. When the electrode expands, it collapses into this hollow space due to the expansion force, potentially leading to electrode breakage. This, in turn, causes a rapid decrease in the battery cell's capacity, affecting its lifespan and reliability. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, one objective of this invention is to provide an electrode assembly for a battery cell, wherein the support portion can support the electrode body, reducing the amount of the electrode body collapsing into the winding hole, thereby reducing the risk of electrode breakage, effectively solving the problem of rapid capacity decline in battery cells, and contributing to improving the service life and reliability of battery cells.

[0004] This utility model further proposes a battery cell.

[0005] The electrode assembly of the battery cell according to this utility model includes:

[0006] A first electrode, a diaphragm, and a second electrode, the diaphragm being located between the first electrode and the second electrode, the first electrode, the diaphragm, and the second electrode being wound together to form an electrode body with a winding hole, the winding hole penetrating the electrode body along a first direction;

[0007] The support portion is located within the winding hole and extends along a first direction. The support portion defines an assembly hole for the winding needle to be inserted, and the support portion forms a through-hole communicating with the assembly hole. A portion of the diaphragm is located within the assembly hole, and the diaphragm passes through the through-hole.

[0008] According to the electrode assembly of the battery cell of this utility model, by setting a support part, the support part can support the electrode body. After the electrode sheet expands, the amount of the electrode body collapsing into the winding hole is reduced, thereby reducing the risk of electrode sheet breakage, effectively solving the problem of rapid capacity decline of battery cell, which is conducive to extending the service life of battery cell and improving the reliability of battery cell.

[0009] In some examples of this utility model, the through gap extends to the edge of the support portion along the first direction.

[0010] In some examples of this utility model, the support part is an arc-shaped structure, and the two ends of the support part are arranged opposite to each other and spaced apart along the circumference of the support part, so as to form a through gap between the two ends of the support part.

[0011] In some examples of this utility model, at least one end of the support portion is provided with an elastic layer along the circumferential direction of the support portion.

[0012] In some examples of this invention, at least a portion of the support is constructed as an elastic structure.

[0013] In some examples of this utility model, the support includes: a plurality of sub-supports, which are connected sequentially along the circumference of the support, and a through gap is formed between two sub-supports located at the ends, and at least one sub-support is an elastic structure.

[0014] In some examples of this invention, the end of the support portion and the end of the electrode body are aligned along the first direction.

[0015] In some examples of this utility model, the inner wall of the assembly hole is formed with a limiting structure, which cooperates with the diaphragm for limiting.

[0016] In some examples of this utility model, the support portion is formed with a weight-reducing structure.

[0017] The battery cell according to this utility model includes:

[0018] shell;

[0019] The electrode assembly is the electrode assembly described above, and the electrode assembly is disposed inside the housing.

[0020] Additional aspects and advantages of this invention 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 invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is an assembly diagram of the electrode assembly and the coiling needle according to an embodiment of the present utility model;

[0023] Figure 2 This is a schematic diagram of an electrode assembly according to an embodiment of the present utility model;

[0024] Figure 3 This is an initial state diagram of the electrode assembly before winding according to an embodiment of the present utility model;

[0025] Figure 4 This is a schematic diagram of the support portion according to an embodiment of the present utility model.

[0026] Figure label:

[0027] Electrode assembly 100;

[0028] First electrode 10; diaphragm 20; second electrode 30; electrode body 40; winding hole 41;

[0029] Support part 50; Assembly hole 51; Through-hole gap 52;

[0030] 300 coil needles. Detailed Implementation

[0031] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0032] The following is for reference. Figures 1-4 The present invention describes an electrode assembly 100 for a battery cell according to an embodiment of the present invention. The battery cell may include a housing defining a mounting cavity, and the electrode assembly 100 is disposed within the mounting cavity.

[0033] like Figures 1-4 As shown, the electrode assembly 100 of the battery cell according to an embodiment of the present invention includes: a first electrode 10, a separator 20, and a second electrode 30, wherein the separator 20 is located between the first electrode 10 and the second electrode 30, the first electrode 10, the separator 20, and the second electrode 30 are wound together to form an electrode body 40 having a winding hole 41, the winding hole 41 penetrating the electrode body 40 along a first direction; and a support portion 50, which is located within the winding hole 41 and extends along the first direction, the support portion 50 defining an assembly hole 51 for a winding needle 300 to extend into, and the support portion 50 forming a through-hole 52 communicating with the assembly hole 51, wherein a portion of the separator 20 is located within the assembly hole 51, and the separator 20 passes through the through-hole 52.

[0034] The electrode assembly 100 includes a first electrode 10, a separator 20, and a second electrode 30. The separator 20 is an insulating component. One of the first electrode 10 and the second electrode 30 is a positive electrode, and the other is a negative electrode. The separator 20 is disposed between the first electrode 10 and the second electrode 30. The first electrode 10, the separator 20, and the second electrode 30 are wound together to form an electrode body 40. The separator 20 can separate the first electrode 10 and the second electrode 30, reducing the probability of contact between the first electrode 10 and the second electrode 30, thereby reducing the risk of short circuit in the battery cell caused by contact between the first electrode 10 and the second electrode 30. The electrode body 40 has a winding hole 41 that penetrates the electrode body 40 along a first direction, such as... Figure 2 As shown, when electrode assembly 100 is in Figure 2 When placed in the center direction, the first direction is Figure 2 The X direction in the equation.

[0035] The support portion 50 can be made of rigid plastic or metal. The material used to manufacture the support portion 50 is not specifically limited, as long as it provides a supporting function. The support portion 50 is fitted into the winding hole 41 and extends along a first direction, reaching the end of the electrode body 40. The outer surface of the support portion 50 facing the electrode body 40 can contact the electrode body 40. This outer surface can be smooth to reduce wear on the electrode body 40. The support portion 50 defines a mounting hole 51 that extends through the support portion 50 along the first direction. The mounting hole 51 allows the winding needle 300 to extend into or out of the mounting hole 51 along the first direction. The support portion 50 has a through-hole 52 communicating with the mounting hole 51. A portion of the diaphragm 20 is located within the mounting hole 51, and the diaphragm 20 passes through the through-hole 52.

[0036] As an example, the support portion 50 has an annular structure to define the mounting hole 51. The support portion 50 has a through gap 52 that passes through the support portion 50 radially to connect the mounting hole 51 and the through gap 52. In this embodiment, the support portion 50 has a closed-loop structure, and the through gap 52 extends along a first direction and is located between the two ends of the support portion 50 along the first direction. As another example, the support portion 50 has an arc-shaped structure and is not a closed-loop structure. Along the circumference of the support portion 50, the two ends of the support portion 50 are opposite to each other and spaced apart to form a through gap 52 between the two ends of the support portion 50. In this embodiment, the through gap 52 passes through the support portion 50 along the first direction.

[0037] During the winding of the first electrode 10, the diaphragm 20, and the second electrode 30, the diaphragm 20 passes through the passing gap 52, and part of the structure of the diaphragm 20 is located in the assembly hole 51. The winding needle 300 extends into the assembly hole 51 and clamps the diaphragm 20 located in the assembly hole 51. At least one turn of the diaphragm 20 is pre-wound on the outside of the support part 50. Then, the first electrode 10 and the second electrode 30 are placed on both sides of the diaphragm 20 respectively. The first electrode 10, the diaphragm 20, and the second electrode 30 are wound by the winding needle 300 to form the electrode body 40. After the winding is completed, the winding needle 300 is pulled out from the assembly hole 51, and the support part 50 remains in the winding hole 41 formed by the electrode body 40. The support part 50 and the electrode body 40 flow together into the next production process.

[0038] The support portion 50 is disposed within the winding hole 41 of the electrode body 40. The support portion 50 contacts the electrode body 40 and serves to support the electrode body 40. When at least one of the first electrode 10 and the second electrode 30 expands, the support portion 50 can support the electrode body 40. Compared with the prior art, this reduces the amount of the electrode body 40 collapsing into the winding hole 41, thereby reducing the risk of breakage of the first electrode 10 and the second electrode 30, reducing the probability of sudden capacity decay in the battery cell, extending the battery cell's lifespan, and improving its reliability. Furthermore, a portion of the separator 20 is located within the assembly hole 51, which facilitates the reliable winding of the separator 20 around the outside of the support portion 50. When the support portion 50 is a metal part, it reduces the risk of short circuits caused by the separation portion 50 contacting the electrode due to movement of the separator 20.

[0039] Therefore, by setting the support part 50, the support part 50 can support the electrode body 40. After the electrode sheet expands, the amount of the electrode body 40 collapsing into the winding hole 41 is reduced, which effectively improves the problem of the electrode body 40 collapsing, thereby reducing the risk of electrode sheet breakage, effectively solving the problem of rapid capacity reduction of battery cells, which is conducive to extending the service life of battery cells and improving the reliability of battery cells.

[0040] In some embodiments of this utility model, the through gap 52 extends to the edge of the support portion 50 along the first direction.

[0041] Among them, such as Figure 3 and Figure 4As shown, the through-gap 52 is strip-shaped and extends along a first direction. Along this first direction, the support portion 50 has two edge positions. The two ends of the through-gap 52 extend to the two edge positions of the support portion 50, respectively. In other words, the through-gap 52 penetrates the support portion 50 along the first direction. By extending the through-gap 52 to the edge positions of the support portion 50 along the first direction, the through-gap 52 can penetrate the support portion 50. Before winding the first electrode 10, the diaphragm 20, and the second electrode 30, the diaphragm 20 can be inserted through the through-gap 52 along the first direction. This facilitates the insertion of the diaphragm 20 into the through-gap 52, thereby improving the assembly efficiency of the support portion 50 and the diaphragm 20, and consequently improving the production efficiency of the electrode assembly 100. This makes the arrangement of the through-gap 52 more reasonable.

[0042] In some embodiments of this utility model, the support portion 50 has an arc-shaped structure, and the two ends of the support portion 50 are arranged opposite to each other and spaced apart along the circumference of the support portion 50, so as to form a through gap 52 between the two ends of the support portion 50.

[0043] Among them, such as Figure 3 and Figure 4 As shown, the support portion 50 is constructed in an arc shape. It is not a closed-loop structure and has two ends along its circumference: a first end and a second end. These two ends are positioned opposite each other and spaced apart, thus forming a through-gap 52 between them. Furthermore, by forming the through-gap 52 between the two ends of the support portion 50, the circumferential area of ​​the support portion 50 is increased, thereby increasing the support area for the electrode body 40 and further reducing the amount of collapse of the electrode body 40 into the winding hole 41.

[0044] In some embodiments of the present invention, at least one end of the support portion 50 is provided with an elastic layer (not shown in the figure) along the circumferential direction of the support portion 50.

[0045] Along the circumference of the support portion 50, at least one end of the support portion 50 is provided with an elastic layer. That is, along the circumference of the support portion 50, an elastic layer is provided at one end (one of the first end and the second end), or both ends (one of the first end and the second end) of the support portion 50 are provided with elastic layers. The elastic layer can be bonded and fixed to the support portion 50, or it can be snapped and fixed to the support portion 50. The elastic layer is elastic and can return to its original shape after elastic deformation. The elastic layer can be a rubber layer, a foam layer, etc., but this utility model is not limited to these. The elastic layer can also be made of other elastic materials, as long as the elastic layer is elastic. Since the separator 20 passes through the through-gap 52, along the circumference of the support portion 50, when the end of the support portion 50 supports the separator 20, the separator 20 comes into contact with the elastic layer. The elastic layer plays a buffering role, which can reduce the stress on the separator 20, reduce the risk of stress concentration on the separator 20, thereby reducing the risk of separator breakage and improving the reliability of the battery cell.

[0046] In some embodiments of the present invention, at least a portion of the support portion 50 is configured as an elastic structure.

[0047] At least a portion of the support portion 50 is configured as an elastic structure. This can also be understood as a partial elastic structure or an overall elastic structure. When the entire structure of the support portion 50 is configured as an elastic structure, the support portion 50 can be made of materials such as rubber or plastic. When a portion of the support portion 50 is configured as an elastic structure, that portion can be made of materials such as rubber or plastic, while another portion can be made of metal. The metal portion of the support portion 50 can be injection molded together with the rubber portion. When the electrode body 40 expands and applies pressure to the support portion 50, the support portion 50 can deform to absorb energy, reducing the stress on the electrode and lowering the risk of electrode damage. Furthermore, when the pressure applied by the electrode body 40 to the support portion 50 is less than the elastic force required for the support portion 50 to return to its original shape, the support portion 50 can support the electrode body 40 to return to its original shape, further reducing the amount of collapse of the electrode body 40 into the winding hole 41.

[0048] In some embodiments of the present invention, the support portion 50 includes: a plurality of sub-support portions 50, the plurality of sub-support portions 50 being connected sequentially along the circumference of the support portion 50, a through gap 52 being formed between two sub-support portions 50 located at the ends, and at least one sub-support portion 50 being an elastic structure.

[0049] The support portion 50 may include multiple sub-support portions 50, which may be integrally formed. Each sub-support portion 50 may be configured as an arc-shaped structure, and the number of sub-support portions 50 may be two, three, four, five, or similar. As an example, two sub-support portions 50 are provided, connected circumferentially along the support portion 50, with their free ends facing each other and spaced apart, thus forming a through gap 52 between the free ends of the two sub-support portions 50. As another example, three sub-support portions 50 are provided, connected sequentially circumferentially along the support portion 50, with a through gap 52 formed between the two end sub-support portions 50. At least one sub-support portion 50 is configured as an elastic structure. This application takes as an example that a portion of the multiple sub-support portions 50 are configured as elastic structures. This configuration enables the support portion 50 to have sufficient strength and rigidity. While satisfying the requirement that the support portion 50 supports the electrode body 40, it also enables the support portion 50 to have the ability to deform elastically. This allows the support portion 50 to deform and absorb energy, which can effectively reduce the stress on the electrode and further reduce the risk of electrode damage.

[0050] In some embodiments of this utility model, the end of the support portion 50 and the end of the electrode body 40 are aligned along the first direction.

[0051] Along the first direction, the two ends of the support portion 50 are a first end and a second end, respectively. The first end is aligned with the corresponding end of the electrode body 40, and the second end is aligned with the corresponding end of the electrode body 40. This arrangement helps the support portion 50 support the entire area of ​​the electrode body 40 along the first direction, allowing the support portion 50 to better support the electrode body 40. This further reduces the amount of the electrode body 40 collapsing into the winding hole 41, thereby further reducing the risk of breakage of the first electrode 10 and the second electrode 30, further reducing the probability of sudden capacity decay in the battery cell, and further extending the service life of the battery cell and improving the reliability of the battery cell.

[0052] In some embodiments of this utility model, the inner sidewall of the assembly hole 51 is formed with a limiting structure (not shown in the figure), and the limiting structure is matched with the diaphragm 20 for limiting.

[0053] The inner wall of the assembly hole 51 forms a limiting structure, which can be a limiting boss, structural adhesive, or other structures. As an example, the limiting structure is a limiting boss, with at least one limiting boss. The limiting boss can be integrally formed with the support part 50, or it can be bonded to the support part 50. The diaphragm 20 can have a groove structure, and at least a portion of the limiting boss is assembled within the groove structure, thus enabling the limiting structure to engage with the diaphragm 20. As another example, the limiting structure is a structural adhesive, which is bonded to the support part 50 and to the diaphragm 20, thus enabling the limiting structure to engage with the diaphragm 20. This engagement between the limiting structure and the diaphragm 20 ensures that the diaphragm 20 is reliably positioned on the support part 50, reducing the risk of separation between the support part 50 and the diaphragm 20, reducing the risk of movement of the diaphragm 20 relative to the support part 50, and further reducing the risk of a short circuit caused by the movement of the diaphragm 20 leading to contact between the support part 50 and the electrode.

[0054] In some embodiments of this utility model, the support portion 50 is formed with a weight-reducing structure.

[0055] The weight-reducing structure can be a weight-reducing hole, a weight-reducing groove, etc., and multiple weight-reducing structures can be set, with each structure set at a different position on the support 50. The weight-reducing structure formed on the support 50 helps to reduce the weight of the electrode assembly 100, thereby helping to reduce the weight of the battery cell, and thus helping to achieve a lightweight design for both the electrode assembly 100 and the battery cell.

[0056] A battery cell according to an embodiment of the present invention includes: a housing; and an electrode assembly 100, wherein the electrode assembly 100 is the same as that described in the above embodiment, and the electrode assembly 100 is disposed within the housing. The battery cell can be a cylindrical structure, and the support portion 50 can support the electrode body 40. After the electrode sheet expands, the amount of collapse of the electrode body 40 into the winding hole 41 is reduced, effectively improving the problem of electrode body 40 collapse, thereby reducing the risk of electrode breakage, effectively solving the problem of rapid capacity reduction of the battery cell, which is beneficial to extending the service life of the battery cell and improving the reliability of the battery cell.

[0057] Other components of the battery cell according to the embodiments of the present invention, such as the explosion-proof valve and the electrode post, as well as the operation, are known to those skilled in the art and will not be described in detail here.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An electrode assembly for a single battery cell, characterized in that, include: A first electrode, a diaphragm, and a second electrode, wherein the diaphragm is located between the first electrode and the second electrode, and the first electrode, the diaphragm, and the second electrode are wound together to form an electrode body having a winding hole, wherein the winding hole penetrates the electrode body along a first direction; A support portion is located within the winding hole and extends along the first direction. The support portion defines an assembly hole for the insertion of a winding needle and forms a through-hole communicating with the assembly hole. A portion of the diaphragm is located within the assembly hole and passes through the through-hole.

2. The electrode assembly of the battery cell according to claim 1, characterized in that, Along the first direction, the through-hole extends to the edge of the support portion.

3. The electrode assembly of the battery cell according to claim 1, characterized in that, The support portion has an arc-shaped structure, and along the circumference of the support portion, the two ends of the support portion are arranged opposite to each other and spaced apart to form the through gap between the two ends of the support portion.

4. The electrode assembly of the battery cell according to claim 3, characterized in that, Along the circumferential direction of the support portion, at least one end of the support portion is provided with an elastic layer.

5. The electrode assembly of the battery cell according to claim 3, characterized in that, At least a portion of the support is constructed as an elastic structure.

6. The electrode assembly of the battery cell according to claim 5, characterized in that, The support includes: a plurality of sub-supports, the plurality of sub-supports being connected sequentially along the circumference of the support, a through-gap being formed between two sub-supports located at the ends, and at least one sub-support being an elastic structure.

7. The electrode assembly of the battery cell according to claim 1, characterized in that, Along the first direction, the end of the support portion is aligned with the end of the electrode body.

8. The electrode assembly of the battery cell according to claim 1, characterized in that, The inner wall of the assembly hole forms a limiting structure, which cooperates with the diaphragm for limiting.

9. The electrode assembly of the battery cell according to any one of claims 1-8, characterized in that, The support portion has a weight-reducing structure.

10. A single battery cell, characterized in that, include: shell; An electrode assembly, wherein the electrode assembly is the same as any one of claims 1-9, and the electrode assembly is disposed within the housing.

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