Roll core structure and lithium battery
By setting up an empty foil area on the positive electrode sheet and the negative electrode sheet of the battery core structure and attaching protective tape, the problem of increasing battery thickness is solved, and the battery thickness is reduced and the energy density is improved.
Patent Information
- Application Number
- CN202421744709.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-07-22
AI Technical Summary
Due to the limitation of the pole ear position, the existing battery core structure increases the thickness of the battery, affecting the energy density and battery life.
A core structure is designed in which the positive electrode sheet and the negative electrode sheet are provided with empty foil areas, and protective tape is attached to these areas. After winding, the empty foil area is arranged corresponding to the pole ear, thereby reducing the thickness at the pole ear.
It effectively reduces the battery thickness and improves the battery's energy density and battery life.
Smart Images
Figure CN223006818U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of battery cores, and particularly to a core structure and a lithium battery. Background Art
[0002] With the increasing progress of technology, people's requirements for the performance of electronic products are gradually increasing, such as demands for longer battery life, faster charging speed, and higher working power. To improve the charge and discharge performance of the battery, generally, the tab is arranged in the middle of the electrode sheet. The middle tab can effectively reduce the internal resistance of the battery and improve the rate performance of the battery. However, to ensure the safety of the battery, more protective adhesive tapes are attached at the corresponding tab position, resulting in a thicker thickness at this position than before, reducing the energy density of the battery and being unfavorable for increasing the battery life demand of the product.
[0003] Therefore, there is an urgent need for a core structure that can effectively reduce the thickness of the battery. Summary of the Utility Model
[0004] The purpose of the present disclosure is to overcome the deficiencies in the prior art and provide a core structure and a lithium battery that can effectively reduce the thickness of the battery.
[0005] The purpose of the present disclosure is achieved through the following technical solutions:
[0006] A core structure includes:
[0007] A positive electrode sheet, a positive tab, a negative electrode sheet, a negative tab, and a separator. The positive electrode sheet, the separator, and the negative electrode sheet are stacked and wound. A first connection area is provided in the middle of the positive electrode sheet, and the positive tab is connected to the first connection area. A second connection area is provided in the middle of the negative electrode sheet, and the negative tab is connected to the second connection area.
[0008] The core structure further includes a first protective tape and a second protective tape. The positive electrode sheet further has a first empty foil area, and the first protective tape is adhered to the first empty foil area. After the positive electrode sheet is wound, the first empty foil area is arranged corresponding to the negative tab. The negative electrode sheet further has a second empty foil area, and the second protective tape is adhered to the second empty foil area. After the negative electrode sheet is wound, the second empty foil area is arranged corresponding to the positive tab.
[0009] In one embodiment, the number of the first empty foil areas is two, the number of the first protective tapes is two, the first protective tapes are arranged in one-to-one correspondence with the first empty foil areas. The two first empty foil areas are respectively located on two side surfaces of the positive electrode sheet. After the positive electrode sheet is wound, one of the first empty foil areas is located above the negative tab, and the other first empty foil area is located below the negative tab.
[0010] In one embodiment, the two first empty foil areas are arranged staggeredly with respect to the positive electrode sheet.
[0011] In one embodiment, the number of the second empty foil areas is two, the number of the second protective tapes is two, the second protective tapes are arranged in one-to-one correspondence with the second empty foil areas, the two second empty foil areas are respectively located on two side surfaces of the negative electrode sheet, and after the negative electrode sheet is wound, one of the second empty foil areas is located above the positive electrode tab, and the other second empty foil area is located below the positive electrode tab.
[0012] In one embodiment, the two second empty foil areas are arranged staggeredly with respect to the negative electrode sheet.
[0013] In one embodiment, the area of the first protective tape is larger than the area of the first empty foil area.
[0014] In one embodiment, the area of the second protective tape is larger than the area of the second empty foil area.
[0015] In one embodiment, the core structure further includes a first insulating tape, and the first insulating tape is bonded to the first connection area and covers a partial structure of the positive electrode tab.
[0016] In one embodiment, the core structure further includes a second insulating tape, and the second insulating tape is bonded to the second connection area and covers a partial structure of the negative electrode tab.
[0017] A lithium battery includes the core structure according to any one of the above embodiments.
[0018] Compared with the prior art, the present disclosure has at least the following advantages:
[0019] In the above core structure, the positive electrode sheet is provided with a first empty foil area, that is, no active material coating is applied in the first empty foil area, so that the thickness of the first empty foil area is smaller. The first protective tape is attached in the first empty foil area. After the positive electrode sheet is wound, the first empty foil area is located above or below the negative electrode tab. Similarly, no active material coating is applied in the second empty foil area, and the second protective tape is attached in the second empty foil area. After the negative electrode sheet is wound, the second empty foil area is located above or below the positive electrode. By reducing the active material coating, the thickness at the tab after winding can be effectively reduced. Description of the Drawings
[0020] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present disclosure and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.
[0021] Figure 1 It is a schematic structural diagram of the connection between the positive electrode plate and the positive electrode tab;
[0022] Figure 2 It is a schematic diagram of the connection between the negative electrode plate and the negative electrode tab;
[0023] Figure 3 is Figure 1 and Figure 2 The schematic structural diagram after winding the positive electrode plate and the negative electrode plate shown. Specific Embodiments
[0024] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure content of the present disclosure understood more thoroughly and comprehensively.
[0025] It should be noted that when an element is referred to as "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present disclosure belongs. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0027] The present disclosure provides a core structure, which includes a positive electrode sheet, a positive electrode tab, a negative electrode sheet, a negative electrode tab and a separator. The positive electrode sheet, the separator and the negative electrode sheet are stacked and wound. A first connection area is provided in the middle of the positive electrode sheet, and the positive electrode tab is connected to the first connection area. A second connection area is provided in the middle of the negative electrode sheet, and the negative electrode tab is connected to the second connection area. The core structure further includes a first protective tape and a second protective tape. The positive electrode sheet further has a first empty foil area, and the first protective tape is adhered to the first empty foil area. After the positive electrode sheet is wound, the first empty foil area is arranged corresponding to the negative electrode tab. The negative electrode sheet further has a second empty foil area, and the second protective tape is adhered to the second empty foil area. After the negative electrode sheet is wound, the second empty foil area is arranged corresponding to the positive electrode tab.
[0028] In the above core structure, the positive electrode sheet has a first empty foil area, that is, no active material coating is applied in the first empty foil area, so that the thickness of the first empty foil area is relatively small. The first protective tape is attached to the first empty foil area. After the positive electrode sheet is wound, the first empty foil area is located above or below the negative electrode tab. Similarly, no active material coating is applied in the second empty foil area, and the second protective tape is attached to the second empty foil area. After the negative electrode sheet is wound, the second empty foil area is located above or below the positive electrode tab. By reducing the active material coating, the thickness at the tab after winding can be effectively reduced.
[0029] To better understand the technical solutions and beneficial effects of the present disclosure, the following further describes the present disclosure in detail with specific embodiments:
[0030] As Figures 1 to 3 shown, the core structure 10 of an embodiment includes a positive electrode sheet 100, a positive electrode tab 200, a negative electrode sheet 300, a negative electrode tab 400 and a separator 400a. The positive electrode sheet 100, the separator 400a and the negative electrode sheet 300 are stacked and wound. A first connection area 110 is provided in the middle of the positive electrode sheet 100, and the positive electrode tab 200 is connected to the first connection area 110. A second connection area 310 is provided in the middle of the negative electrode sheet 300, and the negative electrode tab 400 is connected to the second connection area 310 to reduce the internal resistance of the battery and improve the battery rate.
[0031] Further, the core structure 10 further includes a first protective tape 500 and a second protective tape 600. The positive electrode sheet 100 further has a first empty foil area 120. The first protective tape 500 is adhered to the first empty foil area 120. After the positive electrode sheet 100 is wound, the first empty foil area 120 is arranged corresponding to the negative electrode tab 400. Specifically, the first protective tape 500 is used to insulate the first empty foil area 120 from the negative electrode tab 400 after winding. The negative electrode sheet 300 further has a second empty foil area 320. The second protective tape 600 is adhered to the second empty foil area 320. After the negative electrode sheet 300 is wound, the second empty foil area 320 is arranged corresponding to the positive electrode tab 200. Specifically, the second protective tape 600 is used to insulate the second empty foil area 320 from the positive electrode tab 200 after winding. At the same time, it can also make the thickness at the positive and negative electrode tabs lower after winding.
[0032] In this embodiment, after the positive and negative electrode tabs are centered, protective tapes need to be attached to avoid battery short - circuit. The first protective tape 500 is attached to the first empty foil area 120 of the positive electrode sheet 100, and the second protective tape 600 is attached to the second empty foil area 320 of the negative electrode sheet 300. Since the first empty foil area 120 is blocked by the first protective tape 500, the active material coating on the first empty foil area 120 can be removed to reduce the thickness of the first empty foil area 120. Similarly, the active material coating on the second empty foil area 320 can be removed to reduce the thickness of the second empty foil area 320. When the positive electrode sheet 100, the separator 400a, and the negative electrode sheet 300 are stacked and wound, the first empty foil area 120 corresponds to the negative electrode tab 400, that is, the first empty foil area 120 is located above or below the negative electrode tab 400, making the thickness at the negative electrode tab 400 lower. The second empty foil area 320 is located above or below the positive electrode tab 200, making the thickness at the positive electrode tab 200 lower. By reducing the redundant active material coating on the electrode sheet, the battery thickness is effectively reduced and the battery energy density is increased. Further, the positions of the first empty foil area 120 and the second empty foil area 320 can be confirmed through model calculation, and the first empty foil area 120 and the second empty foil area 320 are reserved in the coating process, that is, the first empty foil area 120 and the second empty foil area 320 are not coated with the active material coating during coating.
[0033] For the above-mentioned core structure 10, the positive electrode sheet 100 is provided with a first empty foil area 120, that is, no active material coating is applied in the first empty foil area 120, so that the thickness of the first empty foil area 120 is smaller. The first protective tape 500 is attached in the first empty foil area 120. After the positive electrode sheet 100 is wound, the first empty foil area 120 is located above or below the negative electrode tab 400. Similarly, no active material coating is applied in the second empty foil area 320, and the second protective tape 600 is attached in the second empty foil area 320. After the negative electrode sheet 300 is wound, the second empty foil area 320 is located above or below the positive electrode. By reducing the active material coating, the thickness at the electrode tab after winding can be effectively reduced.
[0034] In one embodiment, the number of the first empty foil areas 120 is two, the number of the first protective tapes 500 is two, the first protective tapes 500 and the first empty foil areas 120 are arranged in one-to-one correspondence. The two first empty foil areas 120 are respectively located on two side surfaces of the positive electrode sheet 100. After the positive electrode sheet 100 is wound, one of the first empty foil areas 120 is located above the negative electrode tab 400, and the other first empty foil area 120 is located below the negative electrode tab 400. In this embodiment, the first empty foil areas 120 are respectively provided on the front and back surfaces of the positive electrode sheet 100, and the two first empty foil areas 120 are both attached with the first protective tapes 500 to avoid battery short circuit. After the positive electrode sheet 100 is wound, the two first empty foil areas 120 are respectively located above and below the negative electrode tab 400, and no active material coating is applied in the two first empty foil areas 120, further reducing the thickness at the negative electrode tab 400.
[0035] In one embodiment, the two first empty foil areas 120 are arranged in a staggered manner with respect to the positive electrode sheet 100. It can be understood that the two first empty foil areas 120 are respectively located on the front and back surfaces of the positive electrode sheet 100, and the two first empty foil areas 120 are arranged in a staggered manner, that is, the two first empty foil areas 120 are not located at the same position on the front and back surfaces of the positive electrode sheet 100, so that after the positive electrode sheet 100 is wound, the two first empty foil areas 120 are respectively located above and below the negative electrode tab 400.
[0036] In one embodiment, the number of the second empty foil areas 320 is two, the number of the second protective tapes 600 is two, the second protective tapes 600 are arranged in one-to-one correspondence with the second empty foil areas 320, the two second empty foil areas 320 are respectively located on two side surfaces of the negative electrode sheet 300, and after the negative electrode sheet 300 is wound, one of the second empty foil areas 320 is located above the positive electrode tab 200, and the other second empty foil area 320 is located below the positive electrode tab 200. In this embodiment, second empty foil areas 320 are respectively arranged on the front and back surfaces of the negative electrode sheet 300, and the two second empty foil areas 320 are both attached with second protective tapes 600 to avoid battery short circuit. After the negative electrode sheet 300 is wound, the two second empty foil areas 320 are respectively located above and below the positive electrode tab 200, and no active material coating is applied to the two second empty foil areas 320, further reducing the thickness at the positive electrode tab 200.
[0037] In one embodiment, the two second empty foil areas 320 are arranged staggeredly with respect to the negative electrode sheet 300. It can be understood that the two second empty foil areas 320 are respectively located on the front and back surfaces of the negative electrode sheet 300, and the two second empty foil areas 320 are arranged staggeredly, that is, the two second empty foil areas 320 are not located at the same position on the front and back surfaces of the negative electrode sheet 300, so that after the negative electrode sheet 300 is wound, the two second empty foil areas 320 are respectively located above and below the positive electrode tab 200.
[0038] As Figure 1 shown, in one embodiment, the area of the first protective tape 500 is larger than the area of the first empty foil area 120. It can be understood that the first protective tape 500 needs to cover the first empty foil area 120, that is, the length and width of the first protective tape 500 are larger than the length and width of the first empty foil area 120, to avoid battery short circuit after the electrode tabs come into contact.
[0039] As Figure 2 shown, in one embodiment, the area of the second protective tape 600 is larger than the area of the second empty foil area 320. It can be understood that the length and width of the second protective tape 600 are larger than the length and width of the second empty foil area 320, so that the first protective tape 500 covers the second empty foil area 320 to avoid battery circuit after the electrode tabs come into contact.
[0040] As Figure 1 and Figure 3As shown, in one embodiment, the core structure 10 further includes a first insulating tape 700, which is bonded to the first connection area 110 and covers a part of the structure of the positive electrode tab 200. It can be understood that after the positive electrode tab 200 is welded to the first connection area 110, a first insulating tape 700 needs to be attached to the first connection area 110 and the positive electrode tab 200 to fix and insulate the positive electrode tab 200, so as to prevent the positive electrode tab 200 from deforming and avoid short circuit when the positive electrode tab 200 contacts other positions of the electrode sheet.
[0041] As Figure 2 and Figure 3 As shown, in one embodiment, the core structure 10 further includes a second insulating tape 800, which is bonded to the second connection area 310 and covers a part of the structure of the negative electrode tab 400. It can be understood that after the negative electrode tab 400 is welded to the second connection area 310, a second insulating tape 800 needs to be attached to the second connection area 310 and the negative electrode tab 400 to fix and insulate the negative electrode tab 400, so as to prevent the negative electrode tab 400 from deforming and avoid short circuit when the negative electrode tab 400 contacts other positions of the electrode sheet.
[0042] The present application also provides a lithium battery, including the core structure 10 described in any of the above embodiments.
[0043] Compared with the prior art, the present disclosure has at least the following advantages:
[0044] In the above-mentioned core structure 10, the positive electrode sheet 100 is provided with a first empty foil area 120, that is, no active material coating is applied in the first empty foil area 120, so that the thickness of the first empty foil area 120 is smaller. A first protective tape 500 is attached in the first empty foil area 120. After the positive electrode sheet 100 is wound, the first empty foil area 120 is located above or below the negative electrode tab 400. Similarly, no active material coating is applied in the second empty foil area 320, and a second protective tape 600 is attached in the second empty foil area 320. After the negative electrode sheet 300 is wound, the second empty foil area 320 is located above or below the positive electrode. By reducing the active material coating, the thickness at the electrode tab after winding can be effectively reduced.
[0045] The above embodiments only represent several implementation manners of the present disclosure, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several deformations and improvements can still be made, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.
Claims
1. A winding core structure, comprising a positive electrode sheet, a positive electrode ear, a negative electrode sheet, a negative electrode ear and a separator, wherein the positive electrode sheet, the separator and the negative electrode sheet are stacked and wound, a first connection area is provided in the middle of the positive electrode sheet, the positive electrode ear is connected to the first connection area, a second connection area is provided in the middle of the negative electrode sheet, the negative electrode ear is connected to the second connection area, characterized in that: The winding core structure also includes a first protective tape and a second protective tape. The positive electrode sheet is also provided with a first empty foil area, and the first protective tape is bonded to the first empty foil area. After the positive electrode sheet is wound, the first empty foil area is arranged corresponding to the negative electrode ear. The negative electrode sheet is also provided with a second empty foil area, and the second protective tape is bonded to the second empty foil area. After the negative electrode sheet is wound, the second empty foil area is arranged corresponding to the positive electrode ear.
2. The winding core structure according to claim 1, characterized in that: The number of the first empty foil areas is two, the number of the first protective tapes is two, the first protective tapes are arranged in one-to-one correspondence with the first empty foil areas, the two first empty foil areas are respectively located on the two sides of the positive electrode sheet, and after the positive electrode sheet is wound, one of the first empty foil areas is located above the negative electrode ear, and the other first empty foil area is located below the negative electrode ear.
3. The winding core structure according to claim 2, characterized in that: The two first empty foil areas are staggered relative to the positive electrode sheet.
4. The winding core structure according to claim 1, characterized in that: The number of the second empty foil areas is two, the number of the second protective tapes is two, the second protective tapes are arranged in one-to-one correspondence with the second empty foil areas, the two second empty foil areas are respectively located on the two sides of the negative electrode sheet, and after the negative electrode sheet is wound, one of the second empty foil areas is located above the positive electrode ear, and the other second empty foil area is located below the positive electrode ear.
5. The winding core structure according to claim 4, characterized in that: The two second empty foil areas are staggered relative to the negative electrode sheet.
6. The winding core structure according to claim 1, characterized in that: The area of the first protective tape is larger than the area of the first empty foil area.
7. The winding core structure according to claim 1, characterized in that: The area of the second protective tape is larger than the area of the second empty foil area.
8. The winding core structure according to claim 1, characterized in that: The winding core structure further includes a first insulating tape, which is bonded to the first connecting area and covers a portion of the structure of the positive electrode tab.
9. The winding core structure according to claim 1, characterized in that: The winding core structure further includes a second insulating tape, which is bonded to the second connecting area and covers a portion of the structure of the negative electrode ear.
10. A lithium battery, characterized in that: The invention comprises the winding core structure according to any one of claims 1 to 9.