Electrode plate, electrode assembly and battery monomer

Abstract

The utility model discloses an electrode pole piece, an electrode assembly and a battery monomer, the electrode pole piece comprises a current collector, the current collector comprises a polymer base material, an anode conductive coating and a cathode conductive coating, the anode conductive coating and the cathode conductive coating are respectively arranged on two sides of the polymer base material in the thickness direction; the positive electrode active material layer is arranged on one side, deviating from the polymer base material, of the positive electrode conductive plating layer; and the negative electrode active material layer is arranged on one side, deviating from the polymer base material, of the negative electrode conductive plating layer. According to the electrode plate disclosed by the utility model, the production efficiency can be improved, the reliability of the battery monomer in the working process is improved, and the difficulty in the design process of the battery monomer is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an electrode plate, an electrode assembly and a battery cell. Background Art

[0002] Lithium batteries offer advantages such as high specific energy, long cycle life, energy conservation, environmental protection, and affordability. Currently, a lithium battery electrode assembly typically consists of a separator, a positive electrode sheet, and a negative electrode sheet. The positive electrode sheet is made by coating a positive current collector with a positive active material, while the negative electrode sheet is made by coating a negative current collector with a negative active material. During assembly, the positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, with many stacking steps involved. To simplify the assembly process, an increasing number of manufacturers are choosing to integrate the positive and negative electrode sheets onto a single sheet.

[0003] Related technology CN109638357A discloses a method for preparing an integrated lithium-ion battery electrode / diaphragm, which includes the following steps: A. Selecting a battery diaphragm, coating the positive electrode slurry on one side of the diaphragm, and rolling it to the required thickness to form a positive electrode surface; then coating the negative electrode slurry on the opposite side of the diaphragm, and rolling it to the required thickness to form a negative electrode surface; B. Coating or plating a conductive metal coating on the surface of the positive electrode surface and the negative electrode surface to form a positive electrode current collector and a negative electrode current collector, respectively, to obtain the corresponding integrated lithium-ion battery electrode / diaphragm.

[0004] The integrated lithium-ion battery electrode / diaphragm made by the above method can reduce the number of stacking times during assembly and increase production efficiency, but the positive and negative electrode surfaces have weak adhesion to the diaphragm, and the positive and negative electrode surfaces are easy to fall off, affecting the reliability of the battery during operation. Utility Model Content

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an electrode plate that can improve the reliability of a battery cell during operation.

[0006] The utility model also provides an electrode assembly having the electrode plate.

[0007] The utility model also provides a battery cell having the electrode assembly.

[0008] According to the first aspect of the present invention, the electrode plate comprises: a current collector, the current collector comprising a polymer substrate, a positive conductive coating and a negative conductive coating, the positive conductive coating and the negative conductive coating are respectively arranged on both sides of the polymer substrate in the thickness direction; a positive active material layer, the positive active material layer is arranged on the side of the positive conductive coating away from the polymer substrate; a negative active material layer, the negative active material layer is arranged on the side of the negative conductive coating away from the polymer substrate; a positive lead-out piece and a positive electrode tab, the positive lead-out piece is connected between the positive conductive coating and the positive electrode tab, and the positive lead-out piece is roll-welded to the positive electrode conductive coating; a negative lead-out piece and a negative electrode tab, the negative lead-out piece is connected between the negative conductive coating and the negative electrode tab, and the negative lead-out piece is roll-welded to the negative electrode conductive coating.

[0009] The electrode plates according to the first aspect of the present invention, on the one hand, can reduce the number of times the electrode plates need to be stacked during battery cell production, thereby improving production efficiency. On the other hand, the connection between the positive and negative conductive coatings and the polymer substrate is highly reliable, which can improve the reliability of the battery cell during operation. Furthermore, the stacked electrode plates are connected in series, and the output voltage of the battery cell can be adjusted by adjusting the number of electrode plates, thereby reducing the difficulty of the battery cell design process.

[0010] According to some embodiments of the present invention, the positive electrode conductive coating is an aluminum coating, and the negative electrode conductive coating is a copper coating.

[0011] According to some embodiments of the present invention, the polymer substrate is one of a PET film, a PI film, and a PP film.

[0012] According to some embodiments of the present invention, the thickness of the positive electrode conductive coating is 0.5 μm-10 μm; and or the thickness of the negative electrode conductive coating is 0.5 μm-10 μm.

[0013] According to some embodiments of the present invention, the thickness of the positive electrode conductive coating is 1 μm-3 μm; and or the thickness of the negative electrode conductive coating is 1 μm-3 μm.

[0014] According to some embodiments of the present invention, the thickness of the polymer substrate is 4 μm-20 μm.

[0015] According to some embodiments of the present invention, the thickness of the polymer substrate is 6 μm-10 μm.

[0016] The electrode assembly according to the second aspect of the present invention comprises: a plurality of electrode plates according to the first aspect of the present invention, wherein the plurality of electrode plates are stacked in the thickness direction; and at least one diaphragm, wherein the diaphragm is arranged between two adjacent electrode plates.

[0017] According to the electrode assembly of the second aspect of the present invention, production efficiency can be improved by providing the electrode pole piece according to the first aspect of the present invention.

[0018] A battery cell according to a third aspect of the present invention includes: the electrode assembly according to the second aspect of the present invention.

[0019] According to the battery cell of the third aspect of the present invention, by providing the electrode assembly according to the second aspect of the present invention, the production efficiency can be improved, the reliability of the battery cell during operation can be improved, and the design difficulty can be reduced.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of an electrode assembly according to an embodiment of the present utility model;

[0022] Figure 2 is a schematic diagram of an electrode plate according to an embodiment of the present utility model;

[0023] Figure 3 yes Figure 2 Schematic diagram of the current collector shown in .

[0024] Reference numerals:

[0025] 1000. Electrode assembly;

[0026] 100. Electrode plate;

[0027] 10. Current collector; 11. Polymer substrate; 12. Positive electrode conductive coating; 13. Negative electrode conductive coating;

[0028] 20. positive electrode active material layer;

[0029] 30. Negative electrode active material layer;

[0030] 40. Positive electrode lead-out piece;

[0031] 50. Negative electrode lead;

[0032] 200. Diaphragm. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] Reference below Figure 1-Figure 3 The electrode plate 100 according to the first embodiment of the present invention is described.

[0035] like Figure 1-Figure 3 As shown, the electrode plate 100 according to the embodiment of the first aspect of the present invention includes: a current collector 10 , a positive electrode active material layer 20 and a negative electrode active material layer 30 .

[0036] Specifically, the current collector 10 includes a polymer substrate 11, a positive electrode conductive coating 12 and a negative electrode conductive coating 13. The positive electrode conductive coating 12 and the negative electrode conductive coating 13 are respectively arranged on both sides of the polymer substrate 11 in the thickness direction. The positive electrode active material layer 20 is arranged on the side of the positive electrode conductive coating 12 away from the polymer substrate 11, and the negative electrode active material layer 30 is arranged on the side of the negative electrode conductive coating 13 away from the polymer substrate 11.

[0037] During the production process, preferably, the positive electrode conductive coating 12 and the negative electrode conductive coating 13 are formed on both sides of the polymer substrate 11 in the thickness direction by evaporation, and then the positive electrode slurry is coated on the side of the positive electrode conductive coating 12 facing away from the polymer substrate 11, and the negative electrode slurry is coated on the side of the negative electrode conductive coating 13 facing away from the polymer substrate 11. The positive electrode slurry and the negative electrode slurry are then dried and then roll-pressed to form the positive electrode active material layer 20 on the surface of the positive electrode conductive coating 12 and the negative electrode active material layer 30 on the surface of the negative electrode conductive coating 13. The positive electrode slurry is one or a mixture of lithium iron phosphate, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, etc., and the negative electrode slurry is one or a mixture of graphite, silicon, silicon oxide, etc.

[0038] Thus, the positive and negative electrode plates in conventional batteries can be integrated onto the polymer substrate 11. The positive and negative electrode conductive coatings 12 and 13 have strong adhesion to the polymer substrate 11. During the operation of the battery cell, the positive and negative electrode conductive coatings 12 and 13 are less likely to fall off the polymer substrate 11, thereby improving the reliability of the battery cell.

[0039] During the assembly process, the electrode sheets 100 are stacked in the thickness direction, and the diaphragm 200 is placed between the electrode sheets 100. It can be understood that the electrode sheets 100 integrate the positive electrode sheets and the negative electrode sheets in a conventional battery. In this way, the number of electrode sheets 100 can be reduced during stacking, thereby improving production efficiency.

[0040] After the assembly is completed, it can be understood by those skilled in the art that the positive active material layer 20 and the negative active material layer 30 of a single electrode plate 100 can form a battery reaction unit, and a potential difference can be generated between the positive active material layer 20 and the negative active material layer 30. At the same time, the battery reaction unit composed of multiple electrode plates 100 is connected in series. Therefore, by adjusting the number of stacked electrode plates 100, the output voltage of the battery cell can be adjusted. In this way, the difficulty of product design can be reduced during the product design process.

[0041] The electrode plates 100 according to the first embodiment of the present invention can, on the one hand, reduce the number of times the electrode plates 100 need to be stacked during battery cell production, thereby improving production efficiency. Furthermore, the connection between the positive and negative conductive coatings 12, 13, and the polymer substrate 11 is highly reliable, thereby improving the reliability of the battery cell during operation. Furthermore, multiple electrode plates 100 are stacked and connected in series. Adjusting the number of electrode plates 100 allows the output voltage of the battery cell to be adjusted, thereby reducing the difficulty of battery cell design.

[0042] In some embodiments of the present invention, the positive electrode conductive coating 12 is an aluminum coating, and the negative electrode conductive coating 13 is a copper coating. This allows the chemical properties of the positive electrode conductive coating 12 and the negative electrode conductive coating 13 to meet the requirements of the electrochemical reaction in the battery cell, thereby allowing the battery cell to be charged and discharged normally.

[0043] In some embodiments of the present invention, the polymer substrate 11 is one of PET (Polyethylene Terephthalate) film, PI (Polyimide Film), and PP (Polypropylene) film. This allows the chemical properties of the polymer substrate 11 to meet the specific needs of the battery cell. During product design, the material of the polymer substrate 11 can be adjusted to meet a wider range of product design requirements.

[0044] In some embodiments of the present invention, the thickness of the positive electrode conductive coating 12 is 0.5 μm-10 μm. For example, the thickness of the positive electrode conductive coating 12 can be 0.5 μm, 0.7 μm, 1.0 μm, 2.4 μm, 3.0 μm, 6.7 μm, 8.3 μm, or 10 μm. Thus, the thickness of the positive electrode conductive coating 12 can be adjusted to meet the needs of use. During the product design process, the thickness of the positive electrode conductive coating 12 can be adjusted to meet more product design requirements.

[0045] In some embodiments of the present invention, the thickness of the negative electrode conductive coating 13 is 0.5 μm-10 μm. For example, the thickness of the negative electrode conductive coating 13 can be 0.5 μm, 1.0 μm, 2.4 μm, 3.0 μm, 6.7 μm, 8.3 μm, or 10 μm. Thus, the thickness of the negative electrode conductive coating 13 can be adjusted to meet the needs of use. During the product design process, the thickness of the negative electrode conductive coating 13 can be adjusted to meet more product design requirements.

[0046] In some embodiments of the present invention, the thickness of the positive electrode conductive coating 12 is 1 μm-3 μm. For example, the thickness of the positive electrode conductive coating 12 can be 1 μm, 1.5 μm, 1.7 μm, 2.6 μm, or 3 μm, thereby further ensuring the effect of the positive electrode conductive coating 12.

[0047] In some embodiments of the present invention, the thickness of the negative electrode conductive coating 13 is 1 μm-3 μm. For example, the thickness of the negative electrode conductive coating 13 can be 1 μm, 1.7 μm, 2.6 μm or 3 μm, thereby further ensuring the effect of the negative electrode conductive coating 13.

[0048] In some embodiments of the present invention, the thickness of the polymer substrate 11 is 4 μm to 20 μm. For example, the thickness of the polymer substrate 11 can be 4 μm, 6 μm, 7 μm, 10 μm, 15 μm, or 20 μm. Thus, the thickness of the polymer substrate 11 can be adjusted to meet the needs of the product. During the product design process, the thickness of the polymer substrate 11 can be adjusted to meet more product design requirements.

[0049] In some embodiments of the present invention, the thickness of the polymer substrate 11 is 6 μm-10 μm. For example, the thickness of the polymer substrate 11 can be 6 μm, 7 μm or 10 μm, thereby further ensuring the effect of the polymer substrate 11.

[0050] In some embodiments of the present invention, Figure 1 and Figure 2 As shown, the electrode plate 100 further includes: a positive electrode lead-out piece 40, a positive electrode tab, a negative electrode lead-out piece 50 and a negative electrode tab.

[0051] Specifically, the positive electrode lead-out member 40 is connected between the positive electrode conductive coating 12 and the positive electrode tab, and the positive electrode lead-out member 40 is welded to the positive electrode conductive coating 12. The negative electrode lead-out member 50 is connected between the negative electrode conductive coating 13 and the negative electrode tab, and the negative electrode lead-out member 50 is welded to the negative electrode conductive coating 13. In this way, the arrangement of the positive electrode tab and the negative electrode tab on the electrode sheet 100 can be achieved, wherein the welding connection operation is highly efficient and the connection is reliable.

[0052] Among them, preferably, the positive electrode conductive coating 12 is an aluminum coating, the positive electrode lead-out piece 40 is an aluminum material piece, the negative electrode conductive coating 13 is a copper coating, the negative electrode lead-out piece 50 is a copper material piece, the positive electrode lead-out piece 40 is roller-welded to the positive electrode conductive coating 12, and the negative electrode lead-out piece 50 is roller-welded to the negative electrode conductive coating 13.

[0053] Reference below Figure 1-Figure 3 An electrode assembly 1000 according to an embodiment of the second aspect of the present invention is described.

[0054] According to the electrode assembly 1000 of the second embodiment of the present invention, Figure 1 As shown, it includes: a plurality of electrode plates 100 according to the embodiment of the first aspect of the present invention and at least one separator 200. For example, there may be two, three, or ten electrode plates 100, and one, two, or nine separators 200. The plurality of electrode plates 100 are stacked in the thickness direction, and the separator 200 is provided between two adjacent electrode plates 100.

[0055] Preferably, the diaphragm 200 may be one of a PET (Polyethylene Terephthalate) film, a PI (Polyimide Film) film, and a PP (Polypropylene) film.

[0056] During the assembly process, the electrode plates 100 and the diaphragms 200 are stacked in sequence, so that the diaphragm 200 is located between two adjacent electrode plates 100 after the assembly is completed.

[0057] The electrode plate 100 integrates the positive electrode plate and the negative electrode plate in a conventional battery. In this way, the number of times the electrode plates 100 are stacked during the production process can be reduced, and multiple electrode plates 100 are connected in series after being stacked. By adjusting the number of stacked electrode plates 100, the electrode assembly 1000 can meet the output voltage requirements of the battery cell.

[0058] According to the electrode assembly 1000 of the embodiment of the second aspect of the present invention, production efficiency can be improved by providing the electrode plate 100 according to the first aspect of the present invention.

[0059] The battery cell according to the embodiment of the third aspect of the present invention includes: the electrode assembly 1000 according to the embodiment of the second aspect of the present invention.

[0060] According to the battery cell of the third embodiment of the present invention, by providing the electrode assembly 1000 according to the second embodiment of the present invention, the production efficiency can be improved, the reliability of the battery cell during operation can be improved, and the design difficulty can be reduced.

[0061] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0063] In this utility model, unless otherwise expressly specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0065] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An electrode plate, characterized in that: include: A current collector, comprising a polymer substrate, a positive electrode conductive coating, and a negative electrode conductive coating, wherein the positive electrode conductive coating and the negative electrode conductive coating are respectively disposed on both sides of the polymer substrate in a thickness direction; A positive electrode active material layer, the positive electrode active material layer being disposed on a side of the positive electrode conductive coating away from the polymer substrate; A negative electrode active material layer, the negative electrode active material layer being disposed on a side of the negative electrode conductive coating away from the polymer substrate; A positive electrode lead-out piece and a positive electrode tab, wherein the positive electrode lead-out piece is connected between the positive electrode conductive coating and the positive electrode tab, and the positive electrode lead-out piece is connected to the positive electrode conductive coating by roller welding; A negative electrode lead-out piece and a negative electrode tab, wherein the negative electrode lead-out piece is connected between the negative electrode conductive coating and the negative electrode tab, and the negative electrode lead-out piece is connected to the negative electrode conductive coating by roller welding.

2. The electrode plate according to claim 1, characterized in that: The positive electrode conductive coating is an aluminum coating, and the negative electrode conductive coating is a copper coating.

3. The electrode plate according to claim 1, characterized in that: The polymer substrate is one of PET film, PI film and PP film.

4. The electrode plate according to claim 1, characterized in that: The thickness of the positive electrode conductive coating is 0.5 μm-10 μm; and or the thickness of the negative electrode conductive coating is 0.5 μm-10 μm.

5. The electrode plate according to claim 4, characterized in that: The thickness of the positive electrode conductive coating is 1 μm-3 μm; and or the thickness of the negative electrode conductive coating is 1 μm-3 μm.

6. The electrode plate according to claim 1, characterized in that: The thickness of the polymer substrate is 4 μm-20 μm.

7. The electrode plate according to claim 6, characterized in that: The thickness of the polymer substrate is 6 μm-10 μm.

8. An electrode assembly, characterized in that: include: A plurality of electrode plates according to any one of claims 1 to 7, wherein the plurality of electrode plates are stacked in a thickness direction; At least one diaphragm is provided between two adjacent electrode plates.

9. A battery cell, characterized in that: include: The electrode assembly according to claim 8.

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