Pole piece, battery cell and battery
By setting an insulating and wettable substrate layer at the tab and connecting it to the main body, the problem of difficult electrolyte injection in full-tab structure cells is solved, achieving rapid penetration and safe electrolyte injection, and improving the wettability and consistency of the cell.
Patent Information
- Application Number
- CN202423152069.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2034-12-20
AI Technical Summary
The all-tab structure of the battery cell makes it difficult to inject electrolyte during the liquid injection process, which leads to a longer injection time, affects the wettability and consistency of the battery cell, and may cause a short circuit risk after being flattened.
An insulating and wettable substrate layer is provided on the two surfaces of the tab, and connected to the main body through an adhesive layer to form a polar tape, ensuring that the electrolyte quickly penetrates into the cell.
It accelerates the electrolyte dispensing speed, shortens the injection time, improves the wettability and consistency of the battery cell, avoids the risk of short circuits, and enhances the safety performance of the battery cell.
Smart Images
Figure CN223693331U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field especially relates to a pole piece, electric core and battery. BACKGROUND
[0002] With the social development, the application of small cylindrical lithium battery is more and more widely, and the rate performance requirement of electric core is also higher and higher, therefore, the full tab structure electric core is developed, can greatly reduce the internal resistance of electric core, realizes the electric core 15C-20C discharge.
[0003] At present, the cylindrical electric core of full tab structure mostly adopts the mode of welding after tab rubbing flat, but in the process of full tab rubbing flat, the tabs of rubbing flat area can form a blocking layer, leading to the difficulty of electrolyte flowing down when the electric core is injected, lengthening the injection time, affecting the wettability of electrolyte to the electric core, thereby affecting the consistency of electric core, and being not conducive to the packaging of electric core into group. UTILITY MODEL CONTENT
[0004] To solve the above technical problems, the utility model provides a kind of pole piece, electric core and battery, accelerate the liquid of electrolyte when the electric core is injected, shorten injection time, guarantee the consistency of electric core performance.
[0005] The technical scheme adopted by the utility model to solve its technical problems is:
[0006] A battery pole piece, including foil, the foil includes main body part and the tab part of the main body part one side, the main body part both surfaces are equipped with coating, the tab part both surfaces are equipped with matrix layer, and the matrix layer and the main body part have spacing, the matrix layer is insulated, and has wettability to electrolyte.
[0007] Preferably, the tab part and the matrix layer are connected by adhesive layer, and the adhesive layer and the matrix layer form a polar adhesive tape, the thickness of the polar adhesive tape is 10-40 μm.
[0008] Preferably, the thickness of the matrix layer is 5-35 μm.
[0009] Preferably, the thickness of the adhesive layer is 5-35 μm.
[0010] Preferably, the material of the adhesive layer is any one of polyurethane adhesive, polyacrylic resin adhesive, epoxy resin adhesive, organic silicon adhesive and rubber.
[0011] Preferably, the material of the matrix layer is any one of polyether ether ketone, polyimide, polydimethyl terephthalate, polyamide, PVDF, PMMA and polystyrene.
[0012] Preferably, the substrate layer has a width W, and a distance between a lower end surface of the substrate layer and an upper end of the main body part is L, and an upper end surface of the substrate layer is lower than an upper end surface of the tab part;
[0013] W is in a range of 1-5 mm, and L is in a range of 0-2 mm.
[0014] Preferably, the coating layer is made of positive active material and is used to form a positive electrode sheet.
[0015] Or the coating layer is made of negative active material and is used to form a negative electrode sheet.
[0016] An electric core comprises a positive electrode sheet, a negative electrode sheet and a separator, the separator is arranged between the positive electrode sheet and the negative electrode sheet.
[0017] The positive electrode sheet and the negative electrode sheet are both the electrode sheet as described above.
[0018] A battery comprises:
[0019] A shell, the shell has an opening;
[0020] The electric core as described above is arranged in the shell, a positive current collector disc is connected to the tab part of the positive electrode sheet, a negative current collector disc is connected to the tab part of the negative electrode sheet, and the negative current collector disc is connected to a bottom wall of the shell.
[0021] A cap is connected to the shell to cover the opening, and the positive current collector disc is connected to the cap.
[0022] The electric core of the utility model has the advantages of:
[0023] The electric core and the battery are made by adopting the electrode sheet, the two surfaces of the tab part are provided with the substrate layer, the substrate layer has the wettability to the electrolyte, when the substrate layer contacts the electrolyte during the liquid injection, the electrolyte contacts the substrate layer rapidly and penetrates into the electric core rapidly, the liquid injection of the electrolyte is accelerated, the wettability of the electrolyte to the electric core is improved, the liquid injection time is shortened, and the consistency of the electric core is ensured.
[0024] In addition, the substrate layer is insulated, so that after the liquid injection is completed and the electric core is flattened, the substrate layer does not cause the short circuit of the positive and negative electrode materials in the electric core, and the safety performance of the electric core is improved. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 It is a structural schematic view of the electric core of the utility model.
[0026] Figure 2 It is a structural schematic view of the electrode sheet of the utility model.
[0027] Figure 3 This is a schematic diagram of the battery structure of this utility model.
[0028] Wherein: 1-foil, 11-main body, 12-taper, 2-polar tape, 21-base layer, 22-adhesive layer, 3-coating layer;
[0029] 10-Shell, 20-Cell, 201-Electrode, 202-Separator, 30-Cap, 40-Positive current collector, 50-Negative current collector, 60-Insulating sheet. Detailed Implementation
[0030] 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 connection 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.
[0031] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0032] like Figures 1-2 As shown, a preferred embodiment of the present invention provides a battery cell 20, comprising a positive electrode, a negative electrode, and a separator 202, wherein the separator 202 is disposed between the positive electrode and the negative electrode. The positive and negative electrode have the same structure, differing only in the active material they are coated with; for ease of description, they are hereinafter referred to as electrode 201. The electrode 201 comprises a foil 1, which includes a main body 11 and a tab 12 (i.e., the full tab of the battery cell) disposed on one side of the main body 11. Both surfaces of the main body 11 are provided with a coating 3. When the coating 3 is made of a positive active material, a positive electrode is formed; when the coating 3 is made of a negative active material, a negative electrode is formed. Both surfaces of the tab portion 12 are provided with a substrate layer 21. The substrate layer 21 is insulating and has good wettability to electrolyte. For example, its material can be any one or more of polyetheretherketone, polyimide, polydimethyl terephthalate, polyamide, PVDF (polyvinylidene fluoride), PMMA (polymethyl methacrylate), and polystyrene.
[0033] Since the base layer 21 has good wettability to the electrolyte, that is, it can be directly used as the existing polar material, if the base layer 21 directly contacts the main body part 11, the foil 1 of the part of the base layer 21 also forms the main body part 11 instead of being used as a tab, so the base layer 21 needs to have a spacing from the main body part 11, and if the spacing between the lower end surface of the base layer 21 and the upper end of the main body part 11 is L, the value range of L is 0-2 mm, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, etc., or any value or range between any two of the above values.
[0034] Based on the above technical features of the battery cell 20, since both surfaces of the tab part 12 are provided with the base layer 21, and the base layer 21 has wettability to the electrolyte, when the base layer 21 contacts the electrolyte during liquid injection, the electrolyte will quickly contact the base layer 21 and quickly penetrate into the battery cell 20, instead of slowly flowing down from the upper part of the tab after flattening, thereby accelerating the liquid injection of the electrolyte, improving the wettability of the electrolyte to the battery cell 20, shortening the liquid injection time, and ensuring the consistency of the battery cell 20.
[0035] In addition, since the base layer 21 is insulating, it can avoid short circuiting of the positive and negative electrode materials in the battery cell 20 caused by the base layer 21 conducting the battery cell 20 after flattening after liquid injection is completed, thereby improving the safety performance of the battery cell 20.
[0036] In the embodiment, to facilitate the arrangement of the base layer 21 on the tab part 12, an adhesive layer 22 can be arranged between the tab part 12 and the base layer 21, that is, the adhesive layer 22 is connected, which is simple and convenient. Specifically, the adhesive layer 22 and the base layer 21 are integrated to form a polar adhesive tape 2, that is, the polar adhesive tape 2 is directly adhered to the tab part 12, which is simple and convenient to operate. The specific manufacturing method of the battery cell 20 is as follows: coating and slitting are normally performed, the polar adhesive tape 2 is adhered to the tab part 12 of the positive and negative electrode sheets during winding, and then flattening, welding of the current collector, shell entering, spot welding / penetration welding, baking, liquid injection, assembly, film covering, and formation are sequentially performed to finally manufacture the finished battery cell 20.
[0037] In the embodiment, the thickness D of the polar adhesive tape 2 is 10-40 μm, such as 10.5 μm, 20 μm, 20.5 μm, 30 μm, 30.5 μm, or any value or range between any two of the above values. The thickness D1 of the base layer 21 is 5-35 μm, such as 6 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, or any value or range between any two of the above values. The thickness D2 of the adhesive layer 22 is 5-35 μm, such as 6 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, or any value or range between any two of the above values. When specifically configured, since the base layer 21 mainly relies on the electrolyte infiltration and penetration, and the adhesive layer 22 only plays a role of adhesion, the thickness of the base layer 21 can be increased as much as possible to ensure the liquid down effect under the premise of ensuring the adhesion of the polar adhesive tape 2.
[0038] In the embodiment, the polar adhesive tape 2 extends along the length direction of the foil 1, and the width of the polar adhesive tape 2 is less than the width of the tab portion 12, so as to ensure the spacing between the lower end surface of the polar adhesive tape 2 and the upper end of the main body portion 11, and also ensure that the upper end surface of the polar adhesive tape 2 is lower than the upper end surface of the tab portion 12. Specifically, the width of the base layer 21 is W, and the value range of W is 1-5 mm, such as 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or any value or range between any two of the above values. When specifically configured, the width of the polar adhesive tape 2 is configured according to the width of the tab portion 12, so as to ensure that the spacing between the lower end surface of the polar adhesive tape 2 and the upper end of the main body portion 11 is L, and the upper end surface of the polar adhesive tape 2 is lower than the upper end surface of the tab portion 12.
[0039] In order to illustrate the technical effects of the present application, the following specific examples and comparative examples are described.
[0040] Example One
[0041] A roll core with a diameter of 17.8 mm and a height of 61 mm is prepared. When winding, the polar adhesive tape 2 with a width of 2 mm and a thickness of 40 μm is added at a position 2 mm away from the material area on both positive and negative electrode tabs (i.e. L is 2 mm). The adhesive layer 22 is PMMA with a thickness of 5 μm, and the base layer 21 is PVDF with a thickness of 35 μm.
[0042] Example Two
[0043] The method is consistent with that of Example One, except that the width of the polar adhesive tape 2 is changed to 4 mm, and the thickness and material of the adhesive layer 22 and the base layer 21 remain unchanged.
[0044] Example Three
[0045] The method of Example 1 is used, except that the thickness of the adhesive layer 22 is changed to 20 μm and the thickness of the base layer 21 is changed to 20 μm.
[0046] Example Four
[0047] The method of Example 1 is used, except that the thickness of the polar adhesive tape 2 is changed to 25 μm, in which the thickness of the adhesive layer 22 is changed to 5 μm and the thickness of the base layer is changed to 20 μm.
[0048] Example Five
[0049] The method of Example 1 is used, except that the material of the adhesive layer 22 is changed to polyurethane adhesive and the material of the base layer 21 is changed to polyethylene terephthalate.
[0050] Comparative Example One
[0051] The method of Example 1 is used, except that the cell 20 does not contain the polar adhesive tape 2.
[0052] In order to verify the effect of the polar adhesive tape 2, after the above-mentioned winding core is prepared, the 18650 cell is prepared according to the procedures of tab rubbing, current collector welding, shell insertion, penetration welding, assembly, baking, liquid injection, sealing, film covering and formation. The liquid injection rate of electrolyte during liquid injection and the voltage difference between 30 pcs of cells after 30D storage at full charge and 60°C are monitored to verify the consistency of the cell 20.
[0053] The specific verification results are as follows.
[0054]
[0055]
[0056] It can be seen from the comparison between the example and the comparative example that, after the polar adhesive tape 2 is added on the positive and negative tab sides of the full tab, the electrolyte injection time can be greatly shortened and the injection rate can be improved. The base layer 21 plays a major role, which can quickly absorb electrolyte and conduct to the inside of the cell 20, so the thickness of the base layer 21 can be increased as much as possible under the premise of ensuring the adhesion of the polar adhesive tape 2. At the same time, the injection time is shortened, the consistency of the cell 20 injection process is improved, the storage consistency between the cells 20 in the same batch is improved, which is beneficial to the assembly of the cells 20 into a group.
[0057] For example, Figure 3To solve the above technical problems, the application further provides a battery, which comprises a shell 10, the above-mentioned battery cell 20 and a cap 30, the material of the shell 10 is stainless steel, preferably nickel-plated stainless steel, the shell 10 has an opening; the battery cell 20 is arranged in the shell 10 through the opening, the lug part 12 of the positive electrode tab is connected with a positive electrode current collector 40, the lug part 12 of the negative electrode tab is connected with a negative electrode current collector 50, and the negative electrode current collector 50 is connected with the bottom wall of the shell 10; the cap 30 is connected with the shell 10 to cover the opening, and the positive electrode current collector 40 is connected with the cap 30.
[0058] The full-tab battery of the application can effectively accelerate the electrolyte flowing down during the liquid injection of the battery cell, shorten the liquid injection time and ensure the consistency of the performance of the battery cell 20.
[0059] In the embodiment, the positive electrode end of the battery cell 20 is provided with an insulating sheet 60, that is, the insulating sheet 60 separates the lug and the battery cell 20 after being rubbed flat, so as to avoid the lug conducting the positive and negative electrode materials in the battery cell 20 and causing the internal short circuit of the battery cell 20.
[0060] The above-mentioned is only the preferred embodiment of the application, and it should be pointed out that, for the ordinary skilled in the technical field, some improvements and replacements can be made without departing from the technical principles of the application, and these improvements and replacements should also be regarded as the protection range of the application.
Claims
1. A battery pole piece, characterized by: The foil comprises a main body and a tab provided on one side of the main body, both surfaces of the main body are provided with a coating, both surfaces of the tab are provided with a base layer, and the base layer has a spacing with the main body, the base layer is insulated and has wettability to electrolyte.
2. The battery pole piece of claim 1, wherein: The tab and the base layer are connected through an adhesive layer, and the adhesive layer and the base layer form a polar tape, the thickness of the polar tape is 10-40 μm.
3. The battery pole piece of claim 2, wherein: The thickness of the base layer is 5-35 μm.
4. The battery pole piece of claim 2, wherein: The thickness of the adhesive layer is 5-35 μm.
5. The battery pole piece of claim 2, wherein: The material of the adhesive layer is any one of polyurethane adhesive, polyacrylic resin adhesive, epoxy resin adhesive, organic silicon adhesive and rubber.
6. The battery pole piece of any one of claims 1-5, wherein: The material of the base layer is any one of polyether ether ketone, polyimide, polyethylene terephthalate, polyamide, PVDF, PMMA and polystyrene.
7. The battery pole piece of any one of claims 1-5, wherein: The width of the base layer is W, the spacing between the lower end surface of the base layer and the upper end of the main body is L, and the upper end surface of the base layer is lower than the upper end surface of the tab. The value range of W is 1-5 mm, and the value range of L is 0-2 mm.
8. The battery tab according to any one of claims 1-5, characterized in that: The material of the coating is positive active material for forming a positive tab; Or the material of the coating is negative active material for forming a negative tab.
9. An electric cell characterized by: The battery comprises a positive tab, a negative tab and a separator, and the separator is arranged between the positive tab and the negative tab. The positive tab and the negative tab are both the tab of claim 8.
10. A battery, characterized by It comprises: A shell having an opening; The battery cell of claim 9 is arranged in the shell, the tab of the positive tab is connected with a positive current collector, the tab of the negative tab is connected with a negative current collector, and the negative current collector is connected with the bottom wall of the shell; A cap connected to the shell to cover the opening, and the positive current collector is connected to the cap.