Pole piece structure and battery monomer

Abstract

The utility model relates to the technical field of battery pole pieces, and discloses a pole piece structure and a battery monomer, the pole piece structure has a length direction, a width direction and a thickness direction which are pairwise intersected, the pole piece structure comprises a pole piece base material, an active coating and a flexible adhesive layer, and one side of the pole piece base material in the thickness direction is provided with a first surface; the first surface is coated with the active coating, a notch is formed in the active coating in the width direction, and the notch is communicated with the edge of one side of the pole piece base material; the flexible adhesive layers are arranged on the two sides of the notch in the length direction and connected to the edge, close to the notch, of the active coating, the edge, close to the notch, of the first surface and the side face, facing the length direction, of the active coating correspondingly; and the flexible adhesive layers on the two sides are distributed at intervals in the length direction, so that a connecting part for accommodating the tab is formed in the notch. The edge of the notch is wrapped and protected by the flexible adhesive layer, so that the cutting stress of the edge of the notch on the pole piece base material during winding is reduced, and the possibility of pole piece belt breakage caused by large winding pressure is avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery electrode technology, and in particular to an electrode structure and a battery cell. Background Technology

[0002] Currently, consumers have increasingly higher performance requirements for lithium-ion batteries. In order to meet the requirements of high energy density, the density of the battery core needs to be further improved during production. Correspondingly, thinner anode foils, even as thin as 4μm, are required.

[0003] like Figure 1 As shown, the electrode structure in the prior art adopts a structural design of electrode substrate 1a and active coating 2a. The active coating 2a is applied to the surface of the electrode substrate 1a. Typically, a laser cleaning process is used to clean the semi-finished electrode structure, removing the corresponding area of ​​the active coating 2a to form a notch 20a. The notch 20a exposes a portion of the surface of the electrode substrate 1a. In subsequent manufacturing processes, the cleaned electrode structure is wound into a core.

[0004] However, during the winding process, due to the thickness difference between the active coating and the notch area in the electrode structure, and with the continuous increase of winding pressure, the electrode substrate will be subjected to greater cutting stress at the edge of the notch, which may cause the electrode to break. Utility Model Content

[0005] The technical problem to be solved by this utility model is that as the winding pressure increases, the electrode substrate will be subjected to greater cutting stress at the edge of the notch, which may cause the electrode to break.

[0006] To solve the above-mentioned technical problems, this utility model provides a technical solution for an electrode structure:

[0007] The electrode structure has intersecting length, width, and thickness directions, including:

[0008] An electrode substrate, wherein the electrode substrate has a first surface on one side in the thickness direction;

[0009] An active coating is applied to the first surface, and the active coating has a notch along the width direction, and the notch connects to one edge of the electrode substrate;

[0010] A flexible adhesive layer is disposed on both sides of the notch along the length direction, and the flexible adhesive layer is respectively connected to the edge of the active coating near the notch, the edge of the first surface near the notch, and the side of the active coating facing the length direction;

[0011] The flexible adhesive layers on both sides of the notch are spaced apart along the length direction to form a connection portion for accommodating the tab inside the notch.

[0012] Furthermore, the notch is groove-shaped, and the active coating has a closed portion in the width direction away from the notch, with the flexible adhesive layer connected to the closed portion.

[0013] Furthermore, the flexible adhesive layer is continuously disposed between the edge of the active coating near the notch and the edge of the first surface near the notch.

[0014] Furthermore, the flexible adhesive layer has a Z-shaped cross-sectional profile in the thickness direction. The flexible adhesive layer includes a first segment, a second segment, and a third segment connecting the first segment and the second segment. The first segment is located on the edge of the active coating near the notch, the second segment is located on the first surface near the edge of the notch, and the third segment is located on the side of the active coating facing the length direction.

[0015] Furthermore, the first segment has a dimension D1 in the length direction, and the second segment has a dimension D2 in the length direction, satisfying 0.5mm≤D1≤2mm and 0.5mm≤D2≤2mm.

[0016] Furthermore, one end of the flexible adhesive layer in the width direction is flush with one edge of the electrode substrate; the other end of the flexible adhesive layer in the width direction protrudes beyond the edge of the notch.

[0017] Furthermore, the flexible adhesive layer is a polyether acrylate adhesive layer.

[0018] Furthermore, the electrode structure also includes an electrode tab, which extends along the width direction and is disposed in the notch. The electrode tab is electrically connected to the connecting portion. A protective film is provided on the surface of the electrode tab in the thickness direction and away from the electrode substrate. In the length direction, the electrode tab and the flexible adhesive layer are distributed at intervals.

[0019] Furthermore, the protective film is embedded in the notch, and the protective film is not higher than the surface of the electrode substrate; in the length direction, the protective film is spaced apart from or in contact with the flexible adhesive layer.

[0020] To solve the above-mentioned technical problems, this utility model provides a technical solution for a single battery cell:

[0021] A single battery cell includes an electrode structure; the electrode structure has intersecting length, width, and thickness directions, including:

[0022] An electrode substrate, wherein the electrode substrate has a first surface on one side in the thickness direction;

[0023] An active coating is applied to the first surface, and the active coating has a notch along the width direction, and the notch connects to one edge of the electrode substrate;

[0024] A flexible adhesive layer is disposed on both sides of the notch along the length direction, and the flexible adhesive layer is respectively connected to the edge of the active coating near the notch, the edge of the first surface near the notch, and the side of the active coating facing the length direction;

[0025] The flexible adhesive layers on both sides of the notch are spaced apart along the length direction to form a connection portion for accommodating the tab inside the notch.

[0026] Furthermore, the notch is groove-shaped, and the active coating has a closed portion in the width direction away from the notch, with the flexible adhesive layer connected to the closed portion.

[0027] Furthermore, the flexible adhesive layer is continuously disposed between the edge of the active coating near the notch and the edge of the first surface near the notch.

[0028] Furthermore, the flexible adhesive layer has a Z-shaped cross-sectional profile in the thickness direction. The flexible adhesive layer includes a first segment, a second segment, and a third segment connecting the first segment and the second segment. The first segment is located on the edge of the active coating near the notch, the second segment is located on the first surface near the edge of the notch, and the third segment is located on the side of the active coating facing the length direction.

[0029] Furthermore, the first segment has a dimension D1 in the length direction, and the second segment has a dimension D2 in the length direction, satisfying 0.5mm≤D1≤2mm and 0.5mm≤D2≤2mm.

[0030] Furthermore, one end of the flexible adhesive layer in the width direction is flush with one edge of the electrode substrate; the other end of the flexible adhesive layer in the width direction protrudes beyond the edge of the notch.

[0031] Furthermore, the flexible adhesive layer is a polyether acrylate adhesive layer.

[0032] Furthermore, the electrode structure also includes an electrode tab, which extends along the width direction and is disposed in the notch. The electrode tab is electrically connected to the connecting portion. A protective film is provided on the surface of the electrode tab in the thickness direction and away from the electrode substrate. In the length direction, the electrode tab and the flexible adhesive layer are distributed at intervals.

[0033] Furthermore, the protective film is embedded in the notch, and the protective film is not higher than the surface of the electrode substrate; in the length direction, the protective film is spaced apart from or in contact with the flexible adhesive layer.

[0034] Compared with the prior art, the electrode structure and battery cell of this utility model have the following advantages: the electrode structure adopts the design of electrode substrate, active coating and flexible adhesive layer. The electrode substrate has a first surface on one side in the thickness direction. The active coating is coated on the first surface of the electrode substrate. The active coating has a notch in the width direction. The notch connects to one side edge of the electrode substrate. The part of the electrode substrate can be exposed at the notch of the active coating to reserve the area for electrical connection tabs.

[0035] Furthermore, the notch extends along the width direction to one edge of the electrode substrate, and flexible adhesive layers are disposed on both sides of the notch along the length direction, with the flexible adhesive layers on both sides spaced apart along the length direction. The tab can be extended along the width direction and arranged in the notch to electrically connect the tab to the connecting part in the notch, and the end of the tab extends out from one edge of the electrode substrate, thus achieving the purpose of connecting and assembling the tab and the electrode substrate.

[0036] The flexible adhesive layer is connected to the edge of the active coating near the notch, the edge of the first surface near the notch, and the side of the active coating facing the length direction. That is, the flexible adhesive layer connects the active coating and the electrode substrate on both sides of the notch along the length direction. On the one hand, this increases the connection area between the active coating and the electrode substrate near the notch; on the other hand, the flexible adhesive layer wraps and protects the edge of the notch, reducing the cutting stress on the electrode substrate caused by the edge of the notch during winding, thus avoiding the problem of electrode breakage caused by high winding pressure. Attached Figure Description

[0037] Figure 1 This is a cross-sectional schematic diagram of the existing electrode structure in the background art along the thickness direction;

[0038] Figure 2 This is a cross-sectional schematic diagram of the electrode structure along the thickness direction in an embodiment of this utility model;

[0039] Figure 3 This is a top view of the electrode substrate and the active coating in an embodiment of this utility model;

[0040] Figure 4 This is a top view schematic diagram of the electrode substrate, active coating and flexible adhesive layer in an embodiment of this utility model;

[0041] Figure 5 This is a top view schematic diagram of the electrode structure in an embodiment of this utility model;

[0042] Figure 1 In the middle: 1a-electrode substrate, 2a-active coating, 20a-notch;

[0043] Figures 2 to 5 In the middle: 1-Electrode substrate, 11-First surface, 12-Connector, 2-Active coating, 20-Notch, 21-Sealed part, 3-Flexible adhesive layer, 31-First segment, 32-Second segment, 33-Third segment, 4-Electrode tab, 5-Protective film, X-Length direction, Y-Width direction, Z-Thickness direction. Detailed Implementation

[0044] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0045] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0048] like Figure 2As shown, an electrode structure according to an embodiment of the present invention has two intersecting length directions X, width directions Y and thickness directions Z, including: electrode substrate 1, active coating 2 and flexible adhesive layer 3. The electrode substrate 1 has a first surface 11 on one side of the thickness direction Z; the active coating 2 is coated on the first surface 11, and the active coating 2 has a notch 20 along the width direction Y, and the notch 20 connects to one edge of the electrode substrate 1.

[0049] Flexible adhesive layers 3 are disposed on both sides of the notch 20 along the length direction X. The flexible adhesive layers 3 are respectively connected to the edge of the active coating 2 near the notch 20, the edge of the first surface 11 near the notch 20, and the side of the active coating 2 facing the length direction X. The flexible adhesive layers 3 on both sides of the notch 20 along the length direction X are distributed at intervals along the length direction X to form a connecting portion 12 for accommodating the tab 4 inside the notch 20.

[0050] The electrode structure adopts the design of electrode substrate 1, active coating 2 and flexible adhesive layer 3. The electrode substrate 1 has a first surface 11 on one side in the thickness direction Z. The active coating 2 is coated on the first surface 11 of the electrode substrate 1. The active coating 2 has a notch 20 along the width direction Y. The notch 20 connects to one side edge of the electrode substrate 1. A part of the surface of the electrode substrate 1 can be exposed at the notch 20 of the active coating 2 to reserve an area for electrical connection tab 4.

[0051] Furthermore, the notch 20 extends along the width direction Y to one edge of the electrode substrate 1, and the flexible adhesive layer 3 is disposed on both sides of the notch 20 along the length direction X, with the flexible adhesive layers 3 on both sides spaced apart along the length direction X. The tab 4 can extend along the width direction Y and be arranged in the notch 20 to electrically connect the tab 4 to the connecting part 12 in the notch 20, and the end of the tab 4 extends out from one edge of the electrode substrate 1, thus achieving the purpose of connecting and assembling the tab 4 and the electrode substrate 1.

[0052] The flexible adhesive layer 3 is connected to the edge of the active coating 2 near the notch 20, the edge of the first surface 11 near the notch 20, and the side of the active coating 2 facing the length direction X. That is, the flexible adhesive layer 3 connects the active coating 2 and the electrode substrate 1 on both sides of the notch 20 along the length direction X. On the one hand, this increases the connection area between the active coating 2 and the electrode substrate 1 near the notch 20; on the other hand, the flexible adhesive layer 3 also wraps and protects the edge of the notch 20, reducing the cutting stress generated by the edge of the notch 20 on the electrode substrate 1 during winding, thus avoiding the problem of electrode breakage caused by high winding pressure.

[0053] In this embodiment, the notch 20 is groove-shaped, and the active coating 2 has a closed portion 21 in the width direction Y and away from the notch 20. The flexible adhesive layer 3 is connected to the closed portion 21. The notch 20 is designed as a groove-shaped notch, and the active coating 2 and the closed portion 21 on both sides of the notch 20 are an integral coating, which not only reserves the area for the electrical connection tab 4, but also ensures the integrity of the active coating 2.

[0054] The flexible adhesive layer 3 is continuously disposed between the edge of the active coating 2 near the notch 20 and the edge of the first surface 11 near the notch 20. The continuous flexible adhesive layer 2 facilitates the dispensing process and provides comprehensive protection for the edge of the notch 20. Specifically, the cross-sectional profile of the flexible adhesive layer 3 in the thickness direction Z is Z-shaped. The flexible adhesive layer 3 covers the first segment 31, the second segment 32, and the third segment 33 connecting the first segment 31 and the second segment 32. The first segment 31 is located at the edge of the active coating 2 near the notch 20, the second segment 32 is located at the edge of the first surface 11 near the notch 20, and the third segment 33 is located on the side of the active coating 2 facing the length direction X.

[0055] It should be noted that the dimension of the first segment 31 in the length direction X is D1, and the dimension of the second segment 32 in the length direction X is D2, satisfying 0.5mm≤D1≤2mm and 0.5mm≤D2≤2mm. In this embodiment, the dimensions of the first segment 31 and the second segment 32 in the length direction X are 0.5mm, 1mm, and 2mm, respectively, or any other size between 0.5mm and 2mm. If this dimension is less than 0.5mm, it may cause the adhesive joint to detach during winding; if this dimension is less than 2mm, the adhesive area will be too large, affecting the density of the core.

[0056] As a further preferred embodiment, one end of the flexible adhesive layer 3 in the width direction Y is flush with one edge of the electrode substrate 1; the other end of the flexible adhesive layer 3 in the width direction Y protrudes beyond the edge of the notch 20. This ensures both the flatness of the end face of the flexible adhesive layer 3 relative to the electrode substrate 1 after winding and expands the bonding range of the flexible adhesive layer 3 in the width direction Y, thereby ensuring that the edge of the notch 20 is completely wrapped and protected. Specifically, the flexible adhesive layer 3 is a polyether acrylate adhesive layer. Polyether acrylate oligomers have good flexibility and tear resistance, meeting the high toughness requirements of greater winding tension.

[0057] The electrode structure also includes a tab 4, which extends along the width direction Y and is disposed in the notch 20. The tab 4 is electrically connected to the connecting part 12. A protective film 5 is provided on the surface of the tab 4 in the thickness direction Z, away from the electrode substrate 1. In the length direction X, the tab 4 and the flexible adhesive layer 3 are distributed alternately. The size of the tab 4 in the length direction X is any size from 4mm to 6mm, and the size of the protective film 5 in the length direction X is any size from 7mm to 10mm.

[0058] The protective film 5 is preferably adhesive paper. It is adhered to the surface of the tab 7 away from the electrode substrate 1, thus eliminating the damaging effect of surface burrs on the tab 4 on the electrode substrate 1 during winding. Furthermore, the protective film 5 is embedded within the notch 20 and does not protrude above the surface of the electrode substrate 1, improving the flatness of the electrode structure. In the longitudinal direction X, the protective film 5 is spaced apart from or in contact with the flexible adhesive layer 3, further reducing the usable width of the protective film 5.

[0059] The fabrication process of the electrode structure of this utility model is as follows:

[0060] Step 1, such as Figure 3 As shown, the active coating 2 on the electrode substrate 1 is cleaned to obtain the electrode substrate 1 and the active coating 2 with notches 20.

[0061] Step 2: Apply adhesive to both sides of the notch 20 along the length X direction. The adhesive is polyether acrylate, and it covers the edge of the active coating 2 near the notch 20, the edge of the first surface 11 near the notch 20, and the side of the active coating 2 facing the length X direction.

[0062] Step 3: Expose the edges of the dispensed notch 20 to UV light to cure the polyether acrylate and form a flexible adhesive layer 3. Figure 4 As shown, this is to prevent the cutting effect caused by the edge of the notch 20 during winding.

[0063] Step 4: Place the tab 4 at the notch 20 and leave a gap between the tab 4 and the flexible adhesive layers 3 on both sides, and weld the tab 4 and the connection part 12 of the electrode substrate 1.

[0064] Step 5: Attach a protective film 5 to the surface of the tab 4 away from the electrode substrate 1, such as... Figure 5 As shown, this is to avoid the surface burrs of the tab 4 from damaging the electrode substrate 1 during winding.

[0065] A specific embodiment of the battery cell of this utility model includes an electrode structure, wherein the electrode structure is the same as the specific embodiments of the electrode structure in the above-described utility model, and will not be repeated here.

[0066] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. An electrode structure having intersecting length directions (X), width directions (Y), and thickness directions (Z), characterized in that, include: Electrode substrate (1), wherein the electrode substrate (1) has a first surface (11) on one side in the thickness direction (Z); An active coating (2) is applied to the first surface (11). The active coating (2) has a notch (20) along the width direction (Y) and the notch (20) connects to one edge of the electrode substrate (1). A flexible adhesive layer (3) is disposed on both sides of the notch (20) along the length direction (X). The flexible adhesive layer (3) is respectively connected to the edge of the active coating (2) near the notch (20), the edge of the first surface (11) near the notch (20), and the side of the active coating (2) facing the length direction (X). The flexible adhesive layers (3) on both sides of the notch (20) along the length direction (X) are spaced apart along the length direction (X) to form a connection portion (12) inside the notch (20) to accommodate the tab (4).

2. The electrode structure according to claim 1, characterized in that, The notch (20) is groove-shaped, and the active coating (2) is provided with a closed portion (21) in the width direction (Y) and away from the notch (20), and the flexible adhesive layer (3) is connected to the closed portion (21).

3. The electrode structure according to claim 1, characterized in that, The flexible adhesive layer (3) is continuously disposed between the edge of the active coating (2) near the notch (20) and the edge of the first surface (11) near the notch (20).

4. The electrode structure according to claim 3, characterized in that, The flexible adhesive layer (3) has a Z-shaped cross-sectional profile in the thickness direction (Z). The flexible adhesive layer (3) includes a first segment (31), a second segment (32), and a third segment (33) connecting the first segment (31) and the second segment (32). The first segment (31) is located on the edge of the active coating (2) near the notch (20). The second segment (32) is located on the first surface (11) near the edge of the notch (20). The third segment (33) is located on the side of the active coating (2) facing the length direction (X).

5. The electrode structure according to claim 4, characterized in that, The first segment (31) has a dimension of D1 in the length direction (X), and the second segment (32) has a dimension of D2 in the length direction (X), satisfying 0.5mm≤D1≤2mm and 0.5mm≤D2≤2mm.

6. The electrode structure according to claim 1, characterized in that, The flexible adhesive layer (3) is flush with one side edge of the electrode substrate (1) at one end in the width direction (Y); the flexible adhesive layer (3) protrudes from the edge of the notch (20) at the other end in the width direction (Y).

7. The electrode structure according to claim 1, characterized in that, The flexible adhesive layer (3) is a polyether acrylate adhesive layer.

8. The electrode structure according to claim 1, characterized in that, The electrode structure also includes an electrode tab (4), which extends along the width direction (Y) and is disposed in the notch (20). The electrode tab (4) is electrically connected to the connecting part (12). The electrode tab (4) has a protective film (5) on the surface of the electrode substrate (1) in the thickness direction (Z) and away from the electrode substrate (1). In the length direction (X), the electrode tab (4) and the flexible adhesive layer (3) are distributed at intervals.

9. The electrode structure according to claim 8, characterized in that, The protective film (5) is embedded in the notch (20), and the protective film (5) is not higher than the surface of the electrode substrate (1); in the length direction (X), the protective film (5) is spaced apart from or in contact with the flexible adhesive layer (3).

10. A single battery cell, characterized in that, Includes the electrode structure as described in any one of claims 1 to 9.

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