Battery cell and battery with same

Abstract

The embodiment of the utility model provides a battery cell and a battery with the same, the battery cell comprises a positive plate, a negative plate and a diaphragm, and the positive plate, the diaphragm and the negative plate are laminated and wound along the winding direction to form a winding battery cell; in the length direction of the battery cell, the negative plate is provided with a first protruding area exceeding the positive plate, and the diaphragm is provided with a second protruding area exceeding the positive plate; a supporting layer is arranged between the first protruding area and the second protruding area. The battery cell provided by the utility model can avoid the problem of deformation of the head part and the tail part in a long-term circulation process.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and particularly relates to battery cells and batteries having the same. Background Technology

[0002] Along the length of the wound battery, the negative electrode is usually larger than the positive electrode, and the side edge of the negative electrode extends beyond the side edge of the positive electrode.

[0003] Because the portion of the negative electrode that extends beyond the positive electrode lacks the support of the positive electrode, the area of ​​the negative electrode extending beyond the positive electrode experiences uneven stress during hot pressing, and cannot adhere tightly to the separator. In subsequent long-term cycling, the portion of the negative electrode extending beyond the positive electrode is prone to lithium plating, which leads to deformation of the portion of the negative electrode extending beyond the positive electrode, and consequently, deformation at the head and tail of the cell. Utility Model Content

[0004] To address the problem of head and tail deformation in battery cells during long-term cycling in related technologies, this utility model provides a battery cell.

[0005] The battery cell of this utility model embodiment includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet, the separator, and the negative electrode sheet are stacked and wound along the winding direction to form the battery cell.

[0006] Along the length of the battery cell, the negative electrode has a first protruding area extending beyond the positive electrode, and the separator has a second protruding area extending beyond the positive electrode.

[0007] A support layer is provided between the first protruding area and the second protruding area.

[0008] The battery cell of this utility model has a support layer between the first protruding area and the second protruding area. The support layer can compensate for the thickness difference between the first and second protruding areas caused by the lack of a positive electrode sheet, thereby supporting the first protruding area of ​​the negative electrode sheet. In the subsequent hot pressing process, on the one hand, the first protruding area of ​​the negative electrode sheet and other parts of the negative electrode sheet are subjected to uniform stress, and on the other hand, the first protruding area of ​​the negative electrode sheet can be tightly bonded to the separator, that is, the first protruding area can be tightly bonded to the second protruding area. This can avoid the problem of lithium plating in the first protruding area during the subsequent long-term cycling process, and thus avoid the problem of deformation of the first protruding area.

[0009] Therefore, the battery cell of this invention can avoid the problem of head and tail deformation during long-term cycling.

[0010] In some embodiments, the support layer is a thickened layer of negative electrode active material disposed on the negative electrode sheet.

[0011] In some embodiments, the support layer is a hot melt adhesive layer coated on the negative electrode sheet.

[0012] In some embodiments, the support layer includes a thickened layer of negative electrode active material integrally formed with the negative electrode sheet and a hot melt adhesive layer coated on the thickened layer of negative electrode active material.

[0013] In some embodiments, the first protruding region has a dimension of 1-2 mm in the length direction of the battery cell.

[0014] In some embodiments, the thickness of the hot melt adhesive layer is 40-60 μm.

[0015] In some embodiments, the hot melt adhesive layer is a sprayed layer.

[0016] In some embodiments, the thickness of the support layer is equal to the thickness of the positive electrode sheet.

[0017] In some embodiments, the thickened layer of the negative electrode active material has the same composition as the negative electrode active material.

[0018] This utility model embodiment also provides a battery, including the battery cell as described in the above embodiment. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the battery cell structure according to an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a battery cell according to another embodiment of the present invention.

[0022] In the picture:

[0023] 1. Positive electrode plate;

[0024] 2. Negative electrode; 201. First protruding area;

[0025] 3. Diaphragm; 301. Second protruding area;

[0026] 4. Support layer; 401. Thickened layer of negative electrode active material; 402. Hot melt adhesive layer. Detailed Implementation

[0027] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0028] In the description of this utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal encapsulation of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] The following is in conjunction with the appendix Figure 1-2 This invention describes the battery cell of an embodiment of the present invention.

[0031] like Figure 1-2 As shown, the head and tail of the wound cell are arranged opposite each other in the length direction of the wound cell, that is, the head and tail of the wound cell are the two ends of the wound cell in its length direction.

[0032] The battery cell of this utility model embodiment includes a positive electrode 1, a negative electrode 2 and a separator 3. The positive electrode 1, the separator 3 and the negative electrode 2 are stacked and wound along the winding direction to form a battery cell.

[0033] Along the length of the cell, the negative electrode 2 has a first protruding region 201 that extends beyond the positive electrode 1, and the separator 3 has a second protruding region 301 that extends beyond the positive electrode 1.

[0034] A support layer 4 is provided between the first protruding area 201 and the second protruding area 301.

[0035] The battery cell of this utility model has a support layer 4 provided between the first protruding area 201 and the second protruding area 301. The support layer 4 can compensate for the thickness difference between the first protruding area 201 and the second protruding area 301 caused by the lack of positive electrode 1, and thus can support the first protruding area 201 of the negative electrode 2. In the subsequent hot pressing process, on the one hand, the first protruding area 201 of the negative electrode 2 and other parts of the negative electrode 2 are subjected to uniform force, and on the other hand, the first protruding area 201 of the negative electrode 2 can be tightly bonded to the separator 3, that is, the first protruding area 201 can be tightly bonded to the second protruding area 301, thereby avoiding the problem of lithium plating in the first protruding area 201 during the subsequent long-term cycling process, and thus avoiding the problem of deformation of the first protruding area 201.

[0036] Therefore, the battery cell of this invention can avoid the problem of head and tail deformation during long-term cycling.

[0037] In some embodiments, such as Figure 2 As shown, the support layer 4 is a thickened layer 401 of negative electrode active material, which is integrally formed with the negative electrode active material on the negative electrode sheet 2.

[0038] The battery cell of this utility model can compensate for the thickness difference between the first protruding area 201 and the second protruding area 301 caused by the lack of positive electrode sheet 1 by setting the support layer 4 as a thickened layer 401 of negative electrode active material. In this way, it can support the first protruding area 201 of the negative electrode sheet 2 and avoid the problem of cyclic deformation of the first protruding area 201 during subsequent long-term cycling.

[0039] In some embodiments, such as Figure 1 As shown, the support layer 4 is a hot melt adhesive layer 402 coated on the negative electrode sheet 2. The hot melt adhesive layer 402 is coated by a spraying process, which can be understood as a sprayed layer.

[0040] The battery cell of this utility model can compensate for the thickness difference between the first protruding area 201 and the second protruding area 301 caused by the lack of positive electrode 1 by setting the support layer 4 as a hot melt adhesive layer 402. In this way, it can support the first protruding area 201 of the negative electrode 2 and avoid the problem of cyclic deformation of the first protruding area 201 during subsequent long-term cycling.

[0041] In some embodiments, the support layer 4 includes a negative electrode active material thickening layer 401 on the negative electrode sheet 2 and a hot melt adhesive layer coated on the negative electrode active material thickening layer 401.

[0042] The battery cell of this utility model can compensate for the thickness difference between the first protruding area 201 and the second protruding area 301 caused by the lack of positive electrode 1 by setting the support layer 4 as a hot melt adhesive layer 402. In this way, it can support the first protruding area 201 of the negative electrode 2 and avoid the problem of cyclic deformation of the first protruding area 201 during subsequent long-term cycling.

[0043] In some embodiments, the first protruding region 201 has a dimension of 1-2 mm in the length direction of the cell.

[0044] In some embodiments, the thickness of the hot melt adhesive layer 402 is 40-60 μm.

[0045] In some embodiments, the thickness of the support layer 4 is equal to the thickness of the positive electrode 1.

[0046] The battery cell of this utility model can compensate for the thickness difference between the first protruding area 201 and the second protruding area 301 caused by the lack of the positive electrode 1 by setting the thickness of the support layer 4 to be equal to the thickness of the positive electrode 1. In this way, the first protruding area 201 of the negative electrode 2 can be supported to avoid the problem of cyclic deformation of the first protruding area 201 during subsequent long-term cycling.

[0047] In some embodiments, the thickened layer 401 of the negative electrode active material has the same composition as the negative electrode active material.

[0048] The battery cell of this utility model has the same composition as the thickened layer 401 of the negative electrode active material, which facilitates processing and eliminates the need to reconfigure the slurry of the thickened layer 401 of the negative electrode active material, thereby reducing processing costs.

[0049] This utility model also provides a battery, including the battery cell of the above embodiment.

[0050] The battery of this utility model embodiment can avoid the problem of head and tail deformation during long-term cycling by setting the battery cell of the above embodiment.

[0051] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A battery cell, characterized in that, The battery cell includes a positive electrode (1), a negative electrode (2), and a separator (3), wherein the positive electrode (1), the separator (3), and the negative electrode (2) are stacked and wound along the winding direction to form the battery cell; In the length direction of the cell, the negative electrode (2) has a first protruding area (201) that extends beyond the positive electrode (1), and the separator (3) has a second protruding area (301) that extends beyond the positive electrode (1). A support layer (4) is provided between the first protruding area (201) and the second protruding area (301).

2. The battery cell according to claim 1, characterized in that, The support layer (4) is a thickened layer (401) of negative electrode active material disposed on the negative electrode sheet (2).

3. The battery cell according to claim 1, characterized in that, The support layer (4) is a hot melt adhesive layer (402) coated on the negative electrode sheet (2).

4. The battery cell according to claim 1, characterized in that, The support layer (4) includes a thickened layer of negative electrode active material (401) integrally formed with the negative electrode sheet (2) and a hot melt adhesive layer coated on the thickened layer of negative electrode active material (401).

5. The battery cell according to claim 1, characterized in that, The first protruding area (201) has a dimension of 1-2 mm in the length direction of the cell.

6. The battery cell according to claim 3, characterized in that, The thickness of the hot melt adhesive layer (402) is 40-60 μm.

7. The battery cell according to claim 3, characterized in that, The hot melt adhesive layer (402) is a sprayed layer.

8. The battery cell according to claim 1, characterized in that, The thickness of the support layer (4) is equal to the thickness of the positive electrode (1).

9. The battery cell according to claim 2, characterized in that, The thickened layer (401) of the negative electrode active material has the same composition as the negative electrode active material.

10. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-9.

Images