Winding battery cell, battery and electric equipment
By adding adhesive tape and a rounded corner structure to the end of the positive electrode sheet of the lithium-ion battery core, the problem of folding at the end of the core was solved, thereby improving the stability and energy density of the battery cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2026-04-03
AI Technical Summary
The tail of the lithium-ion battery core is prone to folding, resulting in bulges on the appearance of the finished battery. Existing adhesive wrapping methods increase thickness or are not applicable, affecting energy density and applicability.
Adhesive paper is placed at the end of the positive electrode plate, and a rounded corner structure is designed at its connection point to avoid the formation of sharp points. The end is fixed by the rounded corners and adhesive paper to prevent folding.
This effectively avoids the problem of folding at the end of the wound cell, while not increasing the cell thickness, thus improving the cell's energy density and applicability.
Smart Images
Figure CN224082457U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a wound battery cell and an electrical device having the same. Background Technology
[0002] With the widespread application of lithium-ion batteries, in order to enhance product competitiveness, lithium-ion batteries are exhibiting diversified dimensions, while increasingly stringent requirements are being placed on their appearance. Currently, the tail end of wound lithium-ion battery cores is prone to folding, resulting in dents on the finished battery's appearance.
[0003] In related technologies, it is common practice to add adhesive to the top and bottom of the battery cell to fix the tail of the cell. However, this method increases the thickness of the core and reduces the energy density of the cell. At the same time, this method is not suitable for all types of battery cells. For narrower battery cells, the distance between the tabs is small, making it impossible to apply adhesive. For battery cells with a small thickness margin, adding adhesive may cause the cell to become too thick. Utility Model Content
[0004] To address the technical problem of battery cores easily folding at the tail in related technologies, this utility model provides a wound battery core.
[0005] The wound battery cell of this utility model embodiment includes: a positive electrode sheet, a negative electrode sheet, and a separator, wherein the positive electrode sheet, the separator, and the negative electrode sheet are stacked and wound along the winding direction to form the wound battery cell;
[0006] In the winding direction, the tail end of the positive electrode wraps around the tail end of the negative electrode;
[0007] The positive electrode sheet has adhesive tape at its tail end;
[0008] The positive electrode sheet has an empty foil area at its tail end. The empty foil area includes a first side, a second side, and a third side connected in sequence. The first side and the third side are arranged opposite to each other in the width direction of the positive electrode sheet.
[0009] The connection between the first side and the second side is provided with a first rounded corner;
[0010] The second side and the third side are provided with a second rounded corner.
[0011] It is understandable that by providing a first rounded corner at the connection between the first and second sides and a second rounded corner at the connection between the second and third sides, the presence of a sharp point in the empty foil area at the tail end of the positive electrode sheet can be avoided, thereby preventing the problem of folding at the connection between the first and second sides and at the connection between the second and third sides.
[0012] Therefore, the wound battery cell of this utility model embodiment has the characteristic that the tail end is not easily folded.
[0013] In some embodiments, the first rounded corner includes a first arc segment and a second arc segment, one end of the first arc segment is connected to the second side, the other end of the first arc segment is connected to one end of the second arc segment, and the other end of the second arc segment is connected to the first side.
[0014] In some embodiments, the radius of the first arc segment is smaller than the radius of the second arc segment.
[0015] In some embodiments, the ratio between the arc length of the first arc segment and the arc length of the second arc segment is 0.2-0.5.
[0016] In some embodiments, the second rounded corner includes a third arc segment and a fourth arc segment, one end of the third arc segment is connected to the second side, the other end of the third arc segment is connected to one end of the fourth arc segment, and the other end of the fourth arc segment is connected to the third side.
[0017] In some embodiments, the radius of the third arc segment is smaller than the radius of the fourth arc segment.
[0018] In some embodiments, the ratio between the arc length of the third arc segment and the arc length of the fourth arc segment is 0.2-0.5.
[0019] In some embodiments, the distance between one end of the adhesive tape and the first rounded corner is 0-3mm, and the distance between the other end of the adhesive tape and the second rounded corner is 0-3mm.
[0020] This utility model also provides a battery, including the wound cell described in the above embodiments.
[0021] This utility model also provides an electrical device, including the battery described in the above embodiments. Attached Figure Description
[0022] 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.
[0023] Figure 1 This is a schematic diagram of the structure of the wound battery cell according to an embodiment of the present invention;
[0024] Figure 2This is a schematic diagram of the structure of the tail end of the wound battery cell in an embodiment of this utility model.
[0025] In the picture:
[0026] 1. Positive electrode plate; 101. Empty foil area; 1011. First side edge; 1012. Second side edge; 1013. Third side edge;
[0027] 2. Negative electrode plate;
[0028] 3. Diaphragm;
[0029] 4. First fillet; 401. First arc segment; 402. Second arc segment;
[0030] 5. Second rounded corner; 501. Third rounded segment; 502. Fourth rounded segment;
[0031] 6. Adhesive tape. Detailed Implementation
[0032] 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.
[0033] 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.
[0034] 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.
[0035] The following is in conjunction with the appendix Figure 1-2 This invention describes a wound battery cell according to an embodiment of the present invention.
[0036] The wound 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 wound battery cell.
[0037] In the winding direction, the tail end of the positive electrode 1 can wrap the tail end of the negative electrode 2. At the same time, the tail end of the positive electrode 1 is provided with adhesive paper 6, which can fix the tail end of the positive electrode 1, thereby fixing the wound battery cell of this utility model embodiment and preventing the wound battery cell of this utility model embodiment from coming loose.
[0038] The positive electrode 1 has an empty foil area 101 at its tail end. The empty foil area 101 does not have an active material layer. The empty foil area 101 includes a first side 1011, a second side 1012, and a third side 1013 connected in sequence. The first side 1011 and the third side 1013 are arranged opposite to each other in the width direction of the positive electrode 1. The connection between the first side 1011 and the second side 1012 is provided with a first rounded corner 4, and the connection between the second side 1012 and the third side 1013 is provided with a second rounded corner 5.
[0039] It is understandable that by providing a first rounded corner 4 at the connection between the first side 1011 and the second side 1012 and a second rounded corner 5 at the connection between the second side 1012 and the third side 1013, the presence of a sharp point in the empty foil area 101 at the tail end of the positive electrode sheet 1 can be avoided. This can prevent the problem of folding at the connection between the first side 1011 and the second side 1012 and at the connection between the second side 1012 and the third side 1013, while also not increasing the thickness of the battery cell.
[0040] Therefore, the wound battery cell of this utility model embodiment has the characteristic that the tail end is not easily folded.
[0041] In some embodiments, the first rounded corner 4 of the wound battery cell of this utility model includes a first rounded segment 401 and a second rounded segment 402. One end of the first rounded segment 401 is connected to the second side 1012, the other end of the first rounded segment 401 is connected to one end of the second rounded segment 402, and the other end of the second rounded segment 402 is connected to the first side 1011.
[0042] Furthermore, the radius of the first circular arc segment 401 is smaller than the radius of the second circular arc segment 402.
[0043] Furthermore, the ratio between the arc length of the first arc segment 401 and the arc length of the second arc segment 402 is 0.2-0.5.
[0044] The wound battery cell of this utility model further avoids the problem of the first rounded corner 4 folding by setting the radius of the first arc segment 401 to be smaller than the radius of the second arc segment 402, and setting the ratio of the arc length of the first arc segment 401 to the arc length of the second arc segment 402 to 0.2-0.5.
[0045] In some embodiments, the second rounded corner 5 of the wound battery cell of this utility model includes a third rounded segment 501 and a fourth rounded segment 502. One end of the third rounded segment 501 is connected to the second side 1012, the other end of the third rounded segment 501 is connected to one end of the fourth rounded segment 502, and the other end of the fourth rounded segment 502 is connected to the third side 1013.
[0046] Furthermore, the radius of the third arc segment 501 is smaller than the radius of the fourth arc segment 502.
[0047] Furthermore, the ratio between the arc length of the third arc segment 501 and the arc length of the fourth arc segment 502 is 0.2-0.5.
[0048] The wound battery cell of this utility model further avoids the problem of the first rounded corner 4 folding by setting the radius of the third arc segment 501 to be smaller than the radius of the fourth arc segment 502, and setting the ratio of the arc length of the third arc segment 501 to the arc length of the fourth arc segment 502 to 0.2-0.5.
[0049] In some embodiments, the distance between one end of the adhesive tape 6 and the first rounded corner 4 is 0-3mm, that is, the distance between one end of the adhesive tape 6 and the connection point between the first rounded corner 4 and the second side 1012 is 0-3mm.
[0050] The distance between the other end of the adhesive tape 6 and the second rounded corner 5 is 0-3mm, that is, the distance between the other end of the adhesive tape 6 and the connection between the second rounded corner 5 and the second side 1012 is 0-3mm.
[0051] Preferably, the distance between one end of the adhesive tape 6 and the first rounded corner 4 is 0mm. That is, one end of the adhesive tape 6 is located at the connection between the first rounded corner 4 and the second side 1012. Setting one end of the adhesive tape 6 at this location can further prevent the first rounded corner 4 from folding.
[0052] Preferably, the distance between the other end of the adhesive tape 6 and the second rounded corner 5 is 0mm. That is, the other end of the adhesive tape 6 is located at the connection between the second rounded corner 5 and the second side 1012. Setting the other end of the adhesive tape 6 at this location can further prevent the second rounded corner 5 from folding.
[0053] This utility model also provides a battery.
[0054] The battery of this utility model embodiment includes the wound cell described in the above embodiment.
[0055] This utility model also provides an electrical device.
[0056] The electrical equipment in this embodiment of the utility model includes the battery described in the above embodiment.
[0057] 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 wound cell, characterized by, The application relates to a battery. The battery comprises: a positive electrode sheet (1), a negative electrode sheet (2) and a separator (3), the positive electrode sheet (1), the separator (3) and the negative electrode sheet (2) being stacked and wound in a winding direction to form a wound battery cell; in the winding direction, a tail end of the positive electrode sheet (1) wraps a tail end of the negative electrode sheet (2); the tail end of the positive electrode sheet (1) is provided with a gum paper (6); the tail end of the positive electrode sheet (1) has an empty foil area (101), the empty foil area (101) comprising a first side edge (1011), a second side edge (1012) and a third side edge (1013) connected in sequence, the first side edge (1011) and the third side edge (1013) being oppositely arranged in a width direction of the positive electrode sheet (1); a first round corner (4) is arranged at a connection position of the first side edge (1011) and the second side edge (1012); 2. The wound cell according to claim 1, characterized by a second round corner (5) is arranged at a connection position of the second side edge (1012) and the third side edge (1013).
3. The wound cell according to claim 2, characterized by The first round corner (4) comprises a first arc segment (401) and a second arc segment (402), one end of the first arc segment (401) is connected with the second side edge (1012), the other end of the first arc segment (401) is connected with one end of the second arc segment (402), and the other end of the second arc segment (402) is connected with the first side edge (1011).
4. The wound cell according to claim 2, wherein The radius of the first arc segment (401) is smaller than the radius of the second arc segment (402).
5. The wound cell according to claim 1, wherein The ratio between the arc length of the first arc segment (401) and the arc length of the second arc segment (402) is 0.2-0.
5.
6. The wound cell according to claim 5, wherein, The second round corner (5) comprises a third arc segment (501) and a fourth arc segment (502), one end of the third arc segment (501) is connected with the second side edge (1012), the other end of the third arc segment (501) is connected with one end of the fourth arc segment (502), and the other end of the fourth arc segment (502) is connected with the third side edge (1013).
7. The wound cell according to claim 5, wherein The radius of the third arc segment (501) is smaller than the radius of the fourth arc segment (502).
8. The wound cell according to claim 1, wherein, The ratio between the arc length of the third arc segment (501) and the arc length of the fourth arc segment (502) is 0.2-0.
5.
9. A battery, characterized by The distance between one end of the gum paper (6) and the first round corner (4) is 0-3 mm, and the distance between the other end of the gum paper (6) and the second round corner (5) is 0-3 mm.
10. An electric device, characterized by The application further provides a battery comprising the wound battery cell. The application further provides a battery comprising the battery.