Pole piece, full-tab cylindrical core and battery

Abstract

This utility model discloses an electrode sheet, a cylindrical core with full tabs, and a battery. The electrode sheet is configured to be stacked with other sheets and wound to form a cylindrical core with full tabs. The electrode sheet includes a main body and a flattening area connected to one end of the main body. The flattening area is provided with a plurality of flattening buffer holes, which are configured to buffer the stress generated in the flattening area during the flattening process and to serve as electrolyte channels after the flattening area is flattened into full tabs. This utility model can buffer the stress generated in the flattening area during the flattening process, reduce the risk of metal shavings generated during flattening, effectively prevent metal shavings from affecting the self-discharge performance of the core, and prevent metal shavings from causing internal short circuits in the battery cell. Moreover, since the plurality of flattening buffer holes can serve as electrolyte channels after the flattening area is flattened into full tabs, the electrolyte wetting effect can be effectively increased, the wetting time can be reduced, and the efficiency of mass production can be improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an electrode sheet, a cylindrical core with multiple tabs, and a battery. Background Technology

[0002] Cylindrical batteries with full tabs have advantages such as low internal resistance and the ability to achieve high-rate charge and discharge. Currently, the full tab structure is mainly achieved using a flattening process. This process involves reserving a blank foil dummy tab area (the area to be flattened) during electrode fabrication. After winding, the dummy tabs are flattened to form a dense conductive end face (full tab) that can be welded to the busbar. The flattening process has advantages such as high production efficiency, good consistency, and controllable bare core height.

[0003] However, existing full-tab flattening processes have some problems. Metal shavings are difficult to avoid during the flattening process, and these shavings can affect the self-discharge performance of the core, potentially causing internal short circuits in the cell. Additionally, the foil density in the flattened area (full tab) is relatively high, making it difficult for electrolyte to penetrate, requiring increased wetting time and reducing production efficiency, becoming a pain point in the industry. Utility Model Content

[0004] The purpose of this utility model is to provide an electrode sheet, a cylindrical winding core with multiple tabs, and a battery, which can solve the problem of...

[0005] To achieve the above objectives, this utility model provides an electrode sheet, which is configured to be stacked with other sheets and then wound to form a full-tab cylindrical core. The electrode sheet includes a main body and a flattening area connected to one end of the main body. The flattening area is provided with a plurality of flattening buffer holes, which are configured to buffer the stress generated in the flattening area during the flattening process and to serve as electrolyte channels after the flattening area is flattened into a full tab.

[0006] Optionally, the plurality of kneading buffer holes are arranged according to the kneading direction and kneading angle.

[0007] Optionally, the plurality of flattening buffer holes are arranged to form multiple rows of flattening buffer holes, and the multiple rows of flattening buffer holes are spaced apart along the winding direction of the electrode sheet. Each row of flattening buffer holes includes multiple linearly arranged flattening buffer holes whose arrangement direction is consistent with the flattening angle.

[0008] Optionally, the angle between the line connecting each of the flattening buffer holes in each row and the long side of the area to be flattened is between 15 and 30°.

[0009] Optionally, the porosity of the area to be kneaded is 10-30%.

[0010] Optionally, the smoothing buffer hole is a circular hole, and the diameter of the smoothing buffer hole is between 0.3 and 1.0 mm.

[0011] Optionally, the thickness of the electrode is between 3.5 and 15 μm.

[0012] Optionally, the electrode is made of electrolytic foil, and the flattening buffer hole is formed by setting a shielding array on the cathode roller; or

[0013] The flattening buffer hole is formed by punching.

[0014] To achieve the above objectives, this utility model also provides a full-tab cylindrical core, which is formed by winding multiple layers of sheets, one or two of which are electrode sheets as described above.

[0015] To achieve the above objectives, this utility model also provides a battery, including the all-tab cylindrical winding core as described above.

[0016] In this embodiment of the invention, the area to be flattened is provided with a plurality of flattening buffer holes. These holes are configured to buffer the stress generated during the flattening process and to serve as electrolyte channels after the area is flattened into full tabs. Because the flattening buffer holes can buffer the stress generated during the flattening process, the risk of metal shavings being generated during flattening is reduced, effectively preventing metal shavings from affecting the self-discharge performance of the core and preventing metal shavings from causing internal short circuits in the battery cell. Furthermore, since the flattening buffer holes can serve as electrolyte channels after the area is flattened into full tabs, the electrolyte wetting effect can be effectively increased, the wetting time reduced, and the efficiency of large-scale production capacity improved, solving the problems of difficult electrolyte wetting and long wetting time in the prior art. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the cathode roller shielding array setting area established according to the height of the area to be kneaded and leveled in this embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the electrode sheet in an embodiment of this utility model.

[0019] Figure 3 This is a schematic diagram of the all-tab cylindrical winding core of this utility model embodiment. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0021] Please see Figures 1 to 3 This utility model embodiment discloses an electrode sheet 1, which is configured to be stacked with other sheets and then wound to form a full-tab cylindrical core 2.

[0022] It should be explained that forming the full-tab cylindrical core 2 by winding does not mean that the full-tab cylindrical core 2 is formed directly after winding; it still needs to be kneaded and leveled.

[0023] It should be noted that electrode 1 can be either a positive electrode or a negative electrode. When electrode 1 is a positive electrode, other sheet materials may include negative electrode materials and separators, etc. When electrode 1 is a negative electrode, other sheet materials may include positive electrode materials and separators, etc.

[0024] The electrode 1 includes a main body 10 and a flattening area 20 connected to one end of the main body 10. The flattening area 20 is provided with a plurality of flattening buffer holes 21. The plurality of flattening buffer holes 21 are configured to buffer the stress generated in the flattening area 20 during the flattening process (stress generated due to compression) and to serve as an electrolyte channel after the flattening area 20 is flattened into a full electrode tab.

[0025] Specifically, the main body 10 is the coated area, and the area to be kneaded 20 is the uncoated area.

[0026] The aforementioned flattening area 20 is well known to those skilled in the art and will not be explained in detail here. After being wound together with other sheets to initially form the full-tab cylindrical core 2, the flattening area 20 is located at one end of the full-tab cylindrical core 2, and will then be flattened to form the full tab.

[0027] In this embodiment of the invention, the flattening area 20 is provided with a plurality of flattening buffer holes 21. These holes 21 are configured to buffer the stress generated in the flattening area 20 during the flattening process and to serve as electrolyte channels after the flattening area 20 is flattened into full tabs. Because the flattening buffer holes 21 can buffer the stress generated in the flattening area 20 during the flattening process, the risk of metal shavings generated during flattening can be reduced, effectively preventing metal shavings from affecting the self-discharge performance of the core and preventing metal shavings from causing internal short circuits in the battery cell. Furthermore, because the flattening buffer holes 21 can serve as electrolyte channels after the flattening area 20 is flattened into full tabs, the electrolyte wetting effect can be effectively increased, the wetting time reduced, and the efficiency of large-scale production capacity improved, solving the problems of difficult electrolyte wetting and long wetting time in the prior art.

[0028] In some embodiments, a plurality of flattening buffer holes 21 are arranged according to the flattening direction and flattening angle, which can effectively buffer the stress generated in the flattening area 20 during the flattening process and significantly reduce the risk of metal chips being generated during flattening.

[0029] It should be noted that the kneading direction refers to whether the kneading is done in a clockwise or counterclockwise direction, and the kneading angle refers to the angle at which the kneading head is kneaded.

[0030] Specifically, a plurality of flattening buffer holes 21 are arranged to form multiple rows of flattening buffer holes 21. These rows are spaced apart along the winding direction of the electrode sheet 1. Each row of flattening buffer holes 21 includes multiple linearly arranged holes 21 whose arrangement direction is consistent with the flattening angle. Because the arrangement direction of each flattening buffer hole 21 in each row is consistent with the flattening angle of the area to be flattened 20 after winding, it can effectively buffer the stress generated in the area to be flattened 20 during the flattening process, significantly reducing the risk of metal shavings generated during flattening. Of course, this is not a limitation.

[0031] In some embodiments, the angle between the line connecting each of the flattening buffer holes 21 in each row of flattening buffer holes 21 and the long side of the flattening area 20 is between 15° and 30°, which is consistent with the flattening angle of the flattening head. Of course, it is not limited to this.

[0032] In some embodiments, the porosity of the flattened zone 20 is 10-30%. Of course, it is not limited to this.

[0033] In some embodiments, the smoothing buffer hole 21 is a circular hole, and the diameter of the smoothing buffer hole 21 is between 0.3 and 1.0 mm. Of course, it is not limited to this. For example, the smoothing buffer hole 21 can also be an elliptical hole, etc.

[0034] In some embodiments, the thickness of electrode 1 is between 3.5 and 15 μm.

[0035] In some embodiments, the electrode 1 is made of electrolytic foil, and the flattening buffer hole 21 is formed by setting a shielding array on the cathode roller. During production, by setting a shielding array on the cathode roller (the flattening buffer hole 21 is formed at the corresponding position of the shielding array), the other production processes of the electrolytic foil remain unchanged, thus enabling mass production of electrolytic foil with flattening buffer holes 21. The produced electrolytic foil can then be slit into multiple electrode sheets 1.

[0036] Specifically, the electrolytic foil is copper foil.

[0037] Specifically, Figure 2 A schematic diagram is provided showing a specific example of establishing a cathode roller shielding array setting area 3 based on the height d of the flattening area 20. In this example, based on the height d of the flattening area 20, a cathode roller shielding array setting area 3 with widths d and 2d is reserved. By setting a shielding array in the cathode roller shielding array setting area 3, an electrolytic foil with flattening buffer holes 21 can be obtained. After coating, rolling and slitting, an electrode 1 can be obtained, with one end of each electrode 1 being the flattening area 20 with flattening buffer holes 21.

[0038] In some embodiments, the flattening buffer hole 21 is formed by punching. To facilitate punching, a special physical die can be used. After the foil with the flattening buffer hole 21 is processed, it can be subsequently slit to form multiple electrode sheets 1.

[0039] Specifically, electrode 1 can be made of rolled foil or electrolytic foil.

[0040] More specifically, the pressed foil is aluminum foil, and the electrolytic foil is copper foil.

[0041] When the electrode 1 is made of electrolytic foil, the flattening buffer hole 21 can be processed using any of the above methods, and the choice can be made according to production needs.

[0042] In some embodiments, after obtaining the foil with the flattening buffer hole 21, the coating-rolling-slitting process can be completed according to the normal sheet making process. Then, it can be wound together with other sheets to initially form the full-tab cylindrical core 2 (at this time, the full tabs have not yet been formed). At this time, the flattening area 20 of the electrode sheet 1 is wound into several turns. Then the flattening operation can be performed.

[0043] Please combine Figures 1 to 3 This utility model embodiment also discloses a full-tab cylindrical core 2, which is formed by winding multiple layers of sheets, one or two of which are the electrode sheets 1 as described above.

[0044] It should be explained that forming the full-tab cylindrical core 2 by winding does not mean that the full-tab cylindrical core 2 is formed directly after winding; it still needs to be kneaded and leveled.

[0045] When one of the sheets is electrode 1, it can be either a negative electrode or a positive electrode. When two of the sheets are electrode 1, they are classified as a negative electrode and a positive electrode.

[0046] This utility model embodiment also discloses a battery, including the all-tab cylindrical winding core 2 as described above.

[0047] Because the several flattening buffer holes 21 can buffer the stress generated in the flattening area 20 during the flattening process, the risk of metal shavings generated during flattening can be reduced, effectively preventing metal shavings from affecting the self-discharge performance of the core and preventing metal shavings from causing internal short circuits in the battery cell. Moreover, since the several flattening buffer holes 21 can serve as electrolyte channels after the flattening area 20 is flattened into full tabs, the electrolyte wetting effect can be effectively increased, the wetting time can be reduced, and the efficiency of mass production can be improved, solving the problems of difficult electrolyte wetting and long wetting time in the prior art.

[0048] The above-disclosed examples are merely preferred embodiments of the present utility model, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model are still within the scope of the present utility model.

Claims

1. An electrode sheet, the electrode sheet being configured to be stacked with other sheets and then wound to form a full-tab cylindrical core, the electrode sheet comprising a main body portion and a flattening area connected to one end of the main body portion, characterized in that, The area to be kneaded is provided with a plurality of kneading buffer holes, which are configured to buffer the stress generated in the area to be kneaded during the kneading process and to serve as electrolyte channels after the area to be kneaded into a full tab.

2. The electrode sheet according to claim 1, characterized in that, The plurality of smoothing buffer holes are arranged according to the smoothing direction and smoothing angle.

3. The electrode sheet according to claim 2, characterized in that, The plurality of flattening buffer holes are arranged to form multiple rows of flattening buffer holes. The multiple rows of flattening buffer holes are spaced apart along the winding direction of the electrode sheet. Each row of flattening buffer holes includes multiple linearly arranged flattening buffer holes whose arrangement direction is consistent with the flattening angle.

4. The electrode sheet according to claim 1, characterized in that, The angle between the line connecting each of the flattening buffer holes in each row and the long side of the area to be flattened is between 15° and 30°.

5. The electrode sheet according to claim 1, characterized in that, The porosity of the area to be kneaded is 10-30%.

6. The electrode sheet according to claim 1, characterized in that, The smoothing buffer hole is a circular hole, and the diameter of the smoothing buffer hole is between 0.3 and 1.0 mm.

7. The electrode sheet according to claim 1, characterized in that, The thickness of the electrode is between 3.5 and 15 μm.

8. The electrode sheet according to claim 1, characterized in that, The electrode is made of electrolytic foil, and the flattening buffer hole is formed by setting a shielding array on the cathode roller; or The flattening buffer hole is formed by punching.

9. A cylindrical wound core with full tabs, characterized in that, It is formed by winding multiple layers of sheets, wherein one or two of the sheets are the electrode sheets according to any one of claims 1 to 8.

10. A battery, characterized in that, Includes the full-tab cylindrical winding core as described in claim 9.

Images