Pole piece and roll core
By sticking adhesive tape on the empty foil area of the electrode and maintaining an appropriate distance, the problem of wrinkling of the electrode during the winding process is solved, and the safety and production efficiency of the battery are improved.
Patent Information
- Application Number
- CN202422708157.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-06
- Publication Date
- 2025-09-05
- Estimated Expiration
- 2034-11-06
AI Technical Summary
The electrode is easily wrinkled when it is wound into sheets, causing the diaphragm to be punctured, resulting in the risk of short circuit, fire or even explosion of the battery cell.
Adhesive tape is pasted on the empty foil area of the pole piece to enhance the strength and maintain a preset distance from the coated area to prevent wrinkles and pole piece flying during the winding process.
It effectively prevents the electrode from wrinkling during the winding process, avoids puncture of the diaphragm, and improves the safety and production efficiency of the battery.
Smart Images
Figure CN223309001U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, in particular to a pole piece and a winding core. Background Art
[0002] Polymer soft-pack lithium-ion batteries are widely used in 3C electronic products due to their flexible and variable shape according to demand. The energy density is gradually increasing, and the current collector foil is becoming thinner and thinner. However, the use of such a thin substrate also brings a serious problem. When the pole piece is wound into the sheet, the empty foil at the head is very likely to wrinkle, reducing production efficiency. At the same time, the wrinkled pole piece core is very likely to pierce the diaphragm, causing problems such as short circuit of the battery cell. In severe cases, it may also cause the risk of fire and explosion of the battery cell. Utility Model Content
[0003] The technical problem to be solved by the embodiments of the present invention is to provide a pole piece and a winding core that can prevent the pole piece from wrinkling during the feeding process, thereby improving safety during use.
[0004] The utility model discloses a pole piece, comprising: a current collector, wherein the current collector has a hollow foil area and a coating area, the coating area is coated with an active material layer, the hollow foil area is located at the initial end of the current collector when it is wound to form a winding core, and adhesive tape is pasted on the hollow foil area, and a preset distance is provided between the adhesive tape and the coating area.
[0005] Optionally, the length of the adhesive tape is greater than 1 / 5 of the length of the empty foil area and less than 1 / 3 of the length of the empty foil area.
[0006] Optionally, the thickness of the adhesive tape is greater than the thickness of the current collector and less than 4 times the thickness of the current collector.
[0007] Optionally, the distance between the edge of the adhesive tape on the side close to the coating area and the coating area is greater than 1 / 3 of the length of the empty foil area.
[0008] Optionally, the distance between the edge of the adhesive tape away from the coating area and the head of the empty foil area is greater than 1 / 3 of the length of the empty foil area.
[0009] Optionally, the adhesive tape and the active material layer are located on the same side of the current collector.
[0010] Optionally, the length of the adhesive tape is 17 mm to 19 mm, the distance between the edge of the adhesive tape close to the coating area and the coating area is 23 mm to 25 mm, the distance between the edge of the adhesive tape away from the coating area and the head of the empty foil area is 18 mm to 20 mm, and the length of the empty foil area is 60 mm to 65 mm.
[0011] Optionally, the adhesive tape is made of polyethylene terephthalate.
[0012] The present utility model also discloses a winding core, comprising a first pole piece, a second pole piece and a diaphragm, wherein the diaphragm is located between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are pole pieces as described above, wherein the active material layers on the first pole piece and the second pole piece correspond to the positive electrode active material layer and the negative electrode active material layer, respectively.
[0013] Optionally, the electrode tape is located at the innermost fold of the reel.
[0014] Compared with the prior art, the beneficial effects of the pole piece and winding core provided by the embodiment of the present invention are as follows: by pasting adhesive tape on the initial end of the current collector used for winding to form the winding core, and the adhesive tape is located in the empty foil area at the initial end, so as to strengthen the empty foil area, it is beneficial to ensure the flatness of the winding during the winding process and avoid wrinkling during the winding process. In addition, there is a preset distance between the adhesive tape and the coating area to prevent the pole piece from flying during the winding process, which is beneficial to ensure the stability of the winding process. The above method can prevent the pole piece from wrinkling during the feeding process, thereby avoiding puncturing the diaphragm and improving safety during use. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in which:
[0016] Figure 1 This is a schematic structural diagram of the current collector provided by an embodiment of the present utility model;
[0017] Figure 2 This is a schematic diagram of the structure of an active material layer coated on a current collector provided by an embodiment of the present utility model;
[0018] Figure 3 It is a structural schematic diagram of the pole piece provided in an embodiment of the present utility model.
[0019] The reference numerals in the figures are:
[0020] 110. Current collector; 112. Empty foil area; 114. Coating area; 116. Active material layer; 118. Adhesive tape. DETAILED DESCRIPTION
[0021] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. Now, in conjunction with the accompanying drawings, a detailed description of the preferred embodiments of the present utility model will be given.
[0022] like Figures 1 to 3As shown, an embodiment of the present invention provides a pole piece, including: a current collector 110, the current collector 110 having a hollow foil area 112 and a coating area 114, the coating area 114 being coated with an active material layer 116, the hollow foil area 112 being located at the initial end of the core formed by winding the current collector 110, and an adhesive tape 118 being pasted on the hollow foil area 112, and a preset distance between the adhesive tape 118 and the coating area 114.
[0023] Specifically, the current collector 110 is made of a very thin foil. The area not coated with the active material layer 116 is the empty foil area 112, and the area coated with the active material layer 116 is the coated area 114. Depending on the different active material layers 116 coated, the current collector 110 can become a positive electrode sheet or a negative electrode sheet after being coated with the active material layer 116 to meet the needs of core winding production.
[0024] Among them, since the current collector 110 itself is relatively thin, the empty foil area 112 is more likely to wrinkle during the process of winding to form a core, which poses a risk of puncturing the diaphragm. In an embodiment of the present application, by pasting adhesive tape 118 on the initial end of the current collector 110 for winding to form a core, and the adhesive tape 118 is located at the empty foil area 112 at the initial end, so as to strengthen the strength of the empty foil area 112, during the winding process, it is beneficial to ensure the flatness of the winding and avoid wrinkling during the winding process. In addition, there is a preset distance between the adhesive tape 118 and the coating area 114, which prevents the pole piece from flying during the winding process, which is beneficial to ensure the stability of the winding process. The above method can prevent the pole piece from wrinkling during the feeding process, thereby avoiding puncturing the diaphragm, thereby improving safety during use.
[0025] In an optional embodiment of the present application, Figure 2 and Figure 3 As shown, the length L2 of the adhesive tape 118 is greater than 1 / 5 of the length L1 of the empty foil area 112 and less than 1 / 3 of the length of the empty foil area 112 .
[0026] Specifically, the length of the adhesive tape 118 and the length of the empty foil area 112 are both lengths extending along the length of the electrode. By setting the length of the adhesive tape 118 to be greater than 1 / 5 of the length of the empty foil area 112, it is helpful to ensure the structural support strength of the empty foil area 112, and avoid the poor effect or lack of corresponding effect caused by the adhesive tape 118 being too short. In addition, setting the length of the adhesive tape 118 to be less than 1 / 3 of the length of the empty foil area 112 can avoid the phenomenon of electrode flying during the winding process due to the excessive length of the adhesive tape 118, which is helpful to improve the stability of the electrode winding process.
[0027] In an optional embodiment of the present application, the thickness of the adhesive tape 118 is greater than the thickness of the current collector 110 and less than 4 times the thickness of the current collector 110 .
[0028] Specifically, if the adhesive tape 118 is too thin, it will be difficult to attach it to the corresponding position of the blank foil area 112, and the improvement in the electrode wrinkling effect will not be significant. If the adhesive tape 118 is too thick, it will be difficult to wind the electrode. Using the adhesive tape 118 thickness specified in the embodiments of this application facilitates the attachment of the adhesive tape 118 and helps ensure the stability of the electrode winding.
[0029] In an optional embodiment of the present application, Figure 2 and Figure 3 As shown, the distance L3 between the edge of the adhesive tape 118 close to the coating area 114 and the coating area 114 is greater than 1 / 3 of the length L1 of the empty foil area 112 .
[0030] By adopting the above-mentioned method, it is possible to prevent the adhesive tape 118 from being too close to the active material layer 116 and affecting the winding effect, thereby improving the reliability of the winding.
[0031] In an optional embodiment of the present application, Figure 2 and Figure 3 As shown, the distance L4 between the edge of the adhesive tape 118 away from the coating area 114 and the head of the empty foil area 112 is greater than 1 / 3 of the length L1 of the empty foil area 112 .
[0032] By adopting the above method, it is possible to ensure that the electrode is located in the middle position of the length direction of the empty foil area 112, and the adhesive paper 118 is at an appropriate distance from the head of the empty foil area 112 and the coating area 114. While ensuring the supporting strength of the adhesive paper 118 to the empty foil area 112, it facilitates the electrode insertion operation during winding, and avoids the adhesive paper 118 from affecting the active material layer 116, so as to ensure the stability of the wound core.
[0033] In an optional embodiment of the present application, the adhesive tape 118 and the active material layer 116 are located on the same side of the current collector 110. This facilitates the pasting operation of the adhesive tape 118 on the current collector 110 and the coating operation of the active material layer 116, thereby improving the convenience during the operation.
[0034] In an optional embodiment of the present application, the length L2 of the adhesive tape 118 is 17 mm to 19 mm, the distance L3 between the edge of the adhesive tape 118 close to the coating area 114 and the coating area 114 is 20 mm to 22 mm, the distance L4 between the edge of the adhesive tape 118 away from the coating area 114 and the head of the empty foil area 112 is 23 mm to 25 mm, and the length L1 of the empty foil area 112 is 60 mm to 65 mm.
[0035] For example, the length L2 of the adhesive tape 118 can be set to 18 mm, the distance L3 between the edge of the adhesive tape 118 near the coated area 114 and the coated area 114 is 22 mm, the distance L4 between the edge of the adhesive tape 118 away from the coated area 114 and the top of the blank foil area 112 is 25 mm, and the length L1 of the blank foil area 112 is 65 mm. In actual operation, floating within the above range can effectively prevent wrinkles.
[0036] In an optional embodiment of the present application, the material of the adhesive tape 118 is polyethylene terephthalate.
[0037] Specifically, polyethylene terephthalate is a commonly used plastic material with high chemical stability and electrical insulation. When used as the adhesive tape 118, it is relatively stable and can also provide a certain strength support, which is conducive to ensuring reliability during use.
[0038] The present utility model also discloses a winding core, including a first electrode piece, a second electrode piece and a diaphragm, wherein the diaphragm is located between the first electrode piece and the second electrode piece, and the first electrode piece and the second electrode piece are the electrode pieces in the aforementioned embodiment, wherein the active material layers 116 on the first electrode piece and the second electrode piece correspond to the positive electrode active material layer and the negative electrode active material layer, respectively.
[0039] Specifically, when the first electrode sheet and the second electrode sheet are wound to form a winding core, the first electrode sheet and the second electrode sheet are both the above-mentioned electrode sheets, and the polarities of the first electrode sheet and the second electrode sheet are opposite. The first electrode sheet can be a positive electrode sheet or a negative electrode sheet; correspondingly, the second electrode sheet can be a negative electrode sheet or a positive electrode sheet. The active material layers 116 provided on the coating areas 114 of the first electrode sheet and the second electrode sheet are different. If the first electrode sheet is a positive electrode sheet, the active material layer 116 provided on the coating area 114 of the first electrode sheet is a positive electrode active material layer. If the first electrode sheet is a negative electrode sheet, the active material layer 116 provided on the coating area 114 of the first electrode sheet is a negative electrode active material layer. Correspondingly, if the second electrode sheet is a negative electrode sheet, the active material layer 116 provided on the coating area 114 of the second electrode sheet is a negative electrode active material layer. If the second electrode sheet is a positive electrode sheet, the active material layer 116 provided on the coating area 114 of the second electrode sheet is a positive electrode active material layer. By adopting the above-mentioned form, the winding core can prevent the electrode from wrinkling, thereby improving safety during use.
[0040] In an optional embodiment of the present application, the electrode tape 118 is located at the innermost fold of the roll core.
[0041] By adopting the above-mentioned method, when the empty foil area 112 cooperates with the winding needle for winding, the flatness of the initial end of the winding can be better guaranteed, and the problem of wrinkles during winding can be avoided, thereby ensuring the reliability of the roll when it is used.
[0042] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Those skilled in the art may modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.
Claims
1. A pole piece, characterized in that: include: A current collector having a hollow foil area and a coated area, the coated area being coated with an active material layer, the hollow foil area being located at the initial end of the current collector being wound to form a roll core, the hollow foil area being pasted with adhesive tape, and a preset distance being provided between the adhesive tape and the coated area.
2. The pole piece according to claim 1, characterized in that: The length of the adhesive tape is greater than 1 / 5 of the length of the empty foil area and less than 1 / 3 of the length of the empty foil area.
3. The pole piece according to claim 2, characterized in that: The thickness of the adhesive tape is greater than the thickness of the current collector and less than 4 times the thickness of the current collector.
4. The pole piece according to claim 1, characterized in that: The distance between the edge of the adhesive tape on the side close to the coating area and the coating area is greater than 1 / 3 of the length of the empty foil area.
5. The pole piece according to claim 1, characterized in that: The distance between the edge of the adhesive tape away from the coating area and the head of the empty foil area is greater than 1 / 3 of the length of the empty foil area.
6. The pole piece according to any one of claims 1 to 5, characterized in that: The adhesive tape and the active material layer are located on the same side of the current collector.
7. The pole piece according to claim 6, characterized in that: The length of the adhesive tape is 17 mm to 19 mm, the distance between the edge of the adhesive tape close to the coating area and the coating area is 20 mm to 22 mm, the distance between the edge of the adhesive tape away from the coating area and the head of the empty foil area is 23 mm to 25 mm, and the length of the empty foil area is 60 mm to 65 mm.
8. The pole piece according to any one of claims 1 to 5, characterized in that: The material of the adhesive tape is polyethylene terephthalate.
9. A winding core, characterized in that: It includes a first electrode piece, a second electrode piece and a diaphragm, the diaphragm is located between the first electrode piece and the second electrode piece, and the first electrode piece and the second electrode piece are the electrode pieces according to any one of claims 1 to 8, wherein the active material layers on the first electrode piece and the second electrode piece correspond to the positive electrode active material layer and the negative electrode active material layer, respectively.
10. The winding core according to claim 9, characterized in that The electrode tape is located at the innermost fold of the winding core.