Method for manufacturing positive electrode plate, positive electrode plate, and battery having the same

Abstract

To provide a method for manufacturing a positive electrode plate having advantages such as uniform thickness, resistance to lithium deposition, and long service life.SOLUTION: A method for manufacturing a positive electrode plate includes the steps of: providing a current collector having a coated area and an uncoated area; applying a positive electrode active material to the coated area of the current collector; cutting the uncoated area at intervals along a length direction of the uncoated area to form a tab between two adjacent cut positions; and cutting off an edge of the positive electrode active material at a location corresponding to the cut position for each cut; and applying an insulating adhesive to an edge of the positive electrode active material located between the two adjacent cut positions, the insulating adhesive being applied to the tab so as to cover a part of the tab.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application is based on and claims priority from a Chinese patent application filed on June 29, 2021, bearing application number 202110727297.1, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of batteries, and in particular to a method for manufacturing a positive electrode plate, a positive electrode plate, and a battery having the same. [Background technology]

[0003] A positive electrode plate is typically formed by applying a positive electrode active material to a current collector. The positive electrode active material can be switched between a liquid state and a solid state. When the positive electrode active material is applied to the current collector in a liquid state, a leveling phenomenon occurs at the edge of the liquid positive electrode active material. Therefore, after the positive electrode active material hardens from the liquid state to the solid state, the thickness of the edge of the positive electrode active material is always smaller than the thickness of the remaining portion of the positive electrode active material.

[0004] When a positive electrode plate and a negative electrode plate are wound or stacked to form a battery cell, the edge of the positive electrode plate is thin, so when the remaining part of the positive electrode plate is attached to the negative electrode plate, there is still a large gap between the edge of the positive electrode plate and the negative electrode plate. During the charge and discharge process of the battery, the ion migration path between the edge of the positive electrode plate and the negative electrode plate is larger than the ion migration path between the remaining part of the positive electrode plate and the negative electrode plate. This results in a large resistance between the edge of the positive electrode plate and the negative electrode plate, making it difficult for ions to insert into the negative electrode. After the battery is cycled multiple times, the conductive ions in the positive electrode active material are likely to crystallize and precipitate.

[0005] In addition, because the gap between the edge of the positive electrode plate and the negative electrode plate is large, more electrolyte needs to be added between the edge of the positive electrode plate and the negative electrode plate to properly release ions from the edge of the positive electrode plate. However, after the battery is cycled multiple times, the electrolyte is consumed, and the electrolyte is easily liberated at the edge of the positive electrode plate, resulting in a shortage of electrolyte between the edge of the positive electrode plate and the negative electrode plate. As a result, the ions at the edge of the positive electrode plate cannot move to the negative electrode plate, and crystallization and precipitation occur. Summary of the Invention

[0006] The present application aims to solve at least one of the technical problems in the prior art, and therefore, one object of the present application is to provide a method for manufacturing a positive electrode plate having advantages such as uniform thickness, resistance to lithium deposition, and long service life.

[0007] The present application further provides a positive plate.

[0008] The present application further provides a battery having the above positive electrode plate.

[0009] To achieve the above object, a method for manufacturing a positive electrode plate according to an embodiment of the first aspect of the present application includes the steps of providing a current collector having a coated region and an uncoated region; coating the coated region of the current collector with a positive electrode active material; cutting the uncoated region at intervals along its length to form tabs between two adjacent cut positions, and trimming off an edge of the positive electrode active material at a location corresponding to the cut position for each cut; and applying an insulating adhesive to an edge of the positive electrode active material located between the two adjacent cut positions.

[0010] The positive electrode plate manufactured by the manufacturing method according to the embodiment of the present application has advantages such as a uniform thickness, resistance to lithium deposition, and a long service life.

[0011] According to some embodiments of the present application, the insulating adhesive is applied to extend over the tab so as to cover a portion of the tab.

[0012] A positive electrode plate according to an embodiment of the second aspect of the present application includes a current collector, a positive electrode active material, and an insulating adhesive, the current collector having a coated area and a non-coated area, at least one tab formed in the non-coated area, cut recesses formed in portions of the coated area located on both sides of the tab along the length direction, the positive electrode active material being coated in the coated area, a thickness of a portion of the positive electrode active material located between adjacent cut recesses being smaller than a thickness of the remaining portion of the positive electrode active material, and the insulating adhesive being coated on a portion of the positive electrode active material located between adjacent cut recesses.

[0013] The positive electrode plate according to the embodiment of the present application has advantages such as a uniform thickness, resistance to lithium deposition, and a long service life.

[0014] According to some embodiments of the present application, the insulating adhesive is applied to extend over the tab so as to cover a portion of the tab.

[0015] According to some embodiments of the present application, the insulating adhesive has an extension length on the tab of 2 mm or less.

[0016] According to some embodiments of the present disclosure, there may be a plurality of tabs, and the plurality of tabs may be spaced apart along the length of the current collector and on at least one side of the current collector in the width direction.

[0017] According to some embodiments of the present application, the insulating adhesive is at least one of polyvinylidene fluoride, styrene butadiene rubber, styrene-isoprene-styrene, and polyacrylate.

[0018] A battery according to an embodiment of the third aspect of the present application includes a positive electrode plate according to an embodiment of the second aspect of the present application, a negative electrode plate, and a separator, the separator being located between the negative electrode plate and the positive electrode plate.

[0019] The battery according to the embodiment of the third aspect of the present application has advantages such as less lithium deposition and a longer service life by utilizing the positive electrode plate according to the embodiment of the second aspect of the present application.

[0020] According to some embodiments of the present application, the negative electrode plate includes a negative electrode active material, the width of the negative electrode active material is greater than the width of the positive electrode active material, and an edge of the negative electrode active material is attached to the insulating adhesive layer.

[0021] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present application. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram of a current collector coated with a positive electrode active material according to the present application. [Figure 2] FIG. 10 is a schematic view of a current collector coated with the positive electrode active material according to the present application, viewed from another angle. [Figure 3] 1 is a schematic structural diagram of a positive electrode plate to which no insulating adhesive is applied according to the present application. [Figure 4] 1 is a schematic structural diagram of a positive electrode plate according to the present application. [Figure 5] 10 is a schematic structural diagram of a positive electrode plate according to the present invention at another viewing angle. FIG. [Figure 6] 1 is a schematic structural diagram of a battery according to the present application. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the preferred embodiments of the present invention will be given. The preferred embodiments described with reference to the accompanying drawings are merely illustrative.

[0024] In the description of this application, the orientations or positional relationships indicated by terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are based on the orientations or positional relationships shown in the drawings, and are intended merely to facilitate and simplify the description of this application. They do not indicate or suggest that the devices or parts shown must have a specific orientation and be configured and operate in a specific orientation, and therefore should not be understood as limiting this application.

[0025] In this description, "plurality" means two or more.

[0026] Hereinafter, a method for manufacturing a positive electrode plate 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0027] As shown in FIGS. 1 to 5, the method for manufacturing the positive electrode plate 1 is as follows: providing a current collector 100 having coated areas 110 and uncoated areas 120; As shown in FIGS. 1 and 2, a step of applying a positive electrode active material 200 to an application area 110 of a current collector 100; As shown in FIG. 3 , cutting the non-coated region 120 at intervals along the length of the non-coated region 120 to form tabs 130 between two adjacent cutting positions, and trimming off the edges of the positive electrode active material 200 at the locations corresponding to the cutting positions each time a cutting is made; 4 and 5, applying insulating adhesive 300 to an edge of positive electrode active material 200 located between two adjacent cutting positions.

[0028] According to the manufacturing method of the positive electrode plate 1 according to the embodiment of the present application, the non-coated region 120 is cut at intervals along the length of the non-coated region 120, thereby forming tabs 130 between two adjacent cutting positions, and each time a cut is made, the edge of the positive electrode active material 200 at a position corresponding to the cutting position is cut off.

[0029] The portion of the positive electrode active material 200 corresponding to the cutting position refers to a region connected to the non-coated region 120 on one side in the width direction of the positive electrode active material 200, and the portion of the coated region 110 connected to the tab 130 is the connection portion 111. That is, the edge of the positive electrode active material 200 is completely cut off except for the portion of the positive electrode active material 200 coated at the connection portion 111 that is not cut off. The edge of the positive electrode active material 200 refers to a region where the thickness of the positive electrode active material 200 is thin.

[0030] As can be seen from this, after the edge of the positive electrode active material 200 corresponding to the cutting position is cut off, the thickness of the remaining portion of the positive electrode active material 200 remains the same except for the positive electrode active material 200 applied to the connection portion 111. In this way, the flatness of the battery 3 including the positive electrode plate 1 is improved, and the phenomenon of ion crystallization and precipitation is less likely to occur after the battery 3 is cycled multiple times, thereby extending the service life of the positive electrode plate 1 and the battery 3.

[0031] For ease of explanation, the present application will hereinafter use an example in which the ions contained in the positive electrode active material 200 are lithium ions. However, it should be understood that the positive electrode active material 200 may also be a paint containing other ions suitable for manufacturing the positive electrode plate 1.

[0032] In addition, insulating adhesive 300 is applied to the edge of the positive electrode active material 200 located between two adjacent cutting positions, and the edges of the positive electrode active material 200 corresponding to the cutting positions are cut off. After that, since the positive electrode active material 200 applied to the connection portion 111 still has a high probability of lithium deposition, insulating adhesive 300 is again applied to the surface of the positive electrode active material 200 applied to the connection portion 111. The insulating adhesive 300 can prevent the formation of a conductive circuit between the positive electrode active material 200 applied to the connection portion 111 and the negative electrode plate 2. Therefore, lithium ions are not released from the positive electrode active material 200 applied to the connection portion 111, further preventing the occurrence of lithium deposition, thereby further extending the service life of the positive electrode 1 and the battery 3.

[0033] Furthermore, the insulating adhesive 300 only needs to be applied to the positive electrode active material 200 at the connection portion 11, i.e., the insulating adhesive 300 does not need to be applied to the entire edge of the positive electrode active material 200, so that the amount of insulating adhesive 300 used can be reduced, thereby reducing costs.

[0034] As described above, the positive electrode plate 1 manufactured by the manufacturing method of the positive electrode plate 1 according to the embodiment of the present application has advantages such as a uniform thickness, resistance to lithium deposition, and a long service life.

[0035] 4 and 5, the insulating adhesive 300 is applied to the tab 130 so as to extend over the tab 130 and cover a portion of the tab 130. In this manner, the insulating adhesive 300 can completely cover the side of the positive electrode active material 200 applied to the connection portion 111 facing the tab 130. This makes it less likely for lithium deposition to occur in the positive electrode active material 200 applied to the connection portion 111, thereby extending the service life of the positive electrode plate 1 and the battery 3.

[0036] Hereinafter, a positive electrode plate 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 4 and 5, the positive electrode plate 1 includes a current collector 100, a positive electrode active material 200, and an insulating adhesive 300.

[0037] The current collector 100 has a coated region 110 and a non-coated region 120, and at least one tab 130 is formed in the non-coated region 120. Cut recesses 140 are formed in portions of the coated region 110 located on both sides of the tab 130 along the longitudinal direction of the coated region 110. The positive electrode active material 200 is coated in the coated region 110, and the thickness of the portions of the positive electrode active material 200 located between adjacent cut recesses 140 is smaller than the thickness of the remaining portion of the positive electrode active material 200. The insulating adhesive 300 is applied to the portions of the positive electrode active material 200 located between adjacent cut recesses 140.

[0038] In this way, except for the portions located between adjacent cut recesses 140, the positive electrode active material 200 in the remaining portions of the positive electrode plate 1 according to the embodiment of the present application has advantages such as a uniform thickness, resistance to lithium deposition, and a long service life.

[0039] 4 and 5, the insulating adhesive 300 is applied to the tab 130 so as to extend over the tab 130 and cover a portion of the tab 130. In this manner, the insulating adhesive 300 can completely cover the side of the positive electrode active material 200 located between the adjacent cut recesses 140 facing the tab 130. This makes the positive electrode active material 200 located between the adjacent cut recesses 140 less susceptible to lithium deposition, thereby extending the service life of the positive electrode plate 1 and the battery 3.

[0040] Specifically, the extending length of the insulating adhesive 300 on the tab 130 is 2 mm or less, and the length of the tab 130 is greater than 2 mm. In this way, not only is it ensured that the insulating adhesive 300 completely covers the portion of the positive electrode active material 200 located between the adjacent cut recesses 140, but it is also possible to prevent the insulating adhesive 300 from covering an area on the tab 130 that is too large, thereby affecting the electrical conductivity between the tab 130 and an external object, and thereby ensure that the positive electrode plate 1 can be used normally.

[0041] 4, there are a plurality of tabs 130, and the plurality of tabs 130 are arranged at intervals along the length of the current collector 100 on at least one side in the width direction of the current collector 100. In this way, by setting the length of the positive electrode plate 1 to be longer, the energy density of the battery 3 including the positive electrode plate 1 can be improved, and the internal resistance of the battery 3 can be reduced, thereby extending the service life of the battery 3.

[0042] According to some specific embodiments of the present application, the insulating adhesive 300 is at least one of polyvinylidene fluoride, styrene-butadiene rubber, styrene-isoprene-styrene, and polyacrylate. In this manner, the insulating adhesive 300 is made of an electrolyte-resistant polymer, which helps to insulate the positive electrode active material 200 between adjacent cut recesses 140, and effectively prevents lithium deposition in the battery 3 including the positive electrode plate 1.

[0043] According to some specific embodiments of the present application, the positive electrode active material 200 includes lithium element, in which case the battery 3 including the positive electrode plate 1 is a lithium battery. In this way, the positive electrode plate 1 can be easily stored and transported, and is environmentally friendly.

[0044] Hereinafter, a battery 3 according to an embodiment of the present invention will be described with reference to the drawings.

[0045] 6, the battery 3 includes a negative electrode plate 2, a separator 4, and a positive electrode plate 1 according to the above-described embodiment of the present application. The separator 4 is located between the negative electrode plate 2 and the positive electrode plate 1. The separator 4 allows ions to pass through but blocks electrons from passing through, thereby preventing spontaneous power generation between the negative electrode plate 2 and the positive electrode plate 1 and improving the reliability of the battery 3.

[0046] The battery 3 according to the embodiment of the present application has advantages such as less lithium deposition and a longer service life due to the use of the positive electrode plate 1 according to the above embodiment of the present application.

[0047] 6 , the negative electrode plate 2 includes a negative electrode active material 400, the width of which is greater than the width of the positive electrode active material 200, and the edge of the negative electrode active material 400 extends to the insulating adhesive 300. In this way, the energy density of the battery 3 can be improved, and the edge of the negative electrode active material 400 can be located between both ends of the insulating adhesive 300.

[0048] Since the insulating adhesive 300 is applied only to the positive electrode active material 200 between adjacent cut recesses 140, i.e., the insulating adhesive 300 is not applied to the remaining portions of the positive electrode active material 200 of the positive electrode plate 300, the remaining portions of the positive electrode active material 200 of the positive electrode plate 300 can all be electrically conductive with the negative electrode plate 2, thereby increasing the energy density of the battery 3.

[0049] The manufacturing method of the positive electrode plate 1 according to the embodiment of the present application, and other configurations and operations of the positive electrode plate 1 and the battery having the same are known to those skilled in the art, and will not be described in detail here.

[0050] In the description herein, when a description refers to a term such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "particular example," or "some examples," it means that the specific feature, structure, material, or characteristic described in combination with the embodiment or example is included in at least one embodiment or example of the present application. In the description herein, the exemplary description for the above term is not necessarily limited to the same embodiment or example.

[0051] Although embodiments of the present application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present application, and that the scope of the present application is limited by the claims and their equivalents. [Explanation of symbols]

[0052] 1 positive electrode plate 2 negative plates 3 batteries 4 Separator 100 Current collector 110 Application area 111 Connection 120 Non-applied area 130 tabs 140 Cutting recess 200 Cathode active material 300 Insulating Adhesive 400 Anode active material

Claims

1. providing a current collector having coated and uncoated areas; applying a positive electrode active material to the application area of ​​the current collector; cutting the non-coated region at intervals along a length of the non-coated region to form tabs between two adjacent cut positions, and trimming off an edge of the positive electrode active material at a location corresponding to the cut position each time a cut is made; and applying an insulating adhesive to an edge of the positive electrode active material located between two adjacent cutting positions.

2. The method for manufacturing an electrode plate according to claim 1 , wherein the insulating adhesive is applied to the tab so as to cover a portion of the tab.

3. A positive electrode plate including a current collector, a positive electrode active material, and an insulating adhesive, the current collector has a coated region and a non-coated region, at least one tab is formed in the non-coated region, and cutting recesses are formed in portions of the coated region located on both sides of the tab along a longitudinal direction thereof; The positive electrode active material is applied to the application region, and a thickness of a portion of the positive electrode active material located between adjacent cut recesses is smaller than a thickness of a remaining portion of the positive electrode active material; and The insulating adhesive is applied to a portion of the positive electrode active material located between adjacent cut recesses.

4. The positive electrode plate according to claim 3 , wherein the insulating adhesive is applied to the tab so as to cover a portion of the tab.

5. The positive electrode plate according to claim 4 , wherein the insulating adhesive has an extending length on the tab of 2 mm or less.

6. The positive electrode plate according to any one of claims 3 to 5, wherein there are a plurality of tabs, and the plurality of tabs are arranged at intervals on at least one side in the width direction of the current collector along the length direction of the current collector.

7. The positive electrode plate according to any one of claims 3 to 6, wherein the insulating adhesive is at least one of polyvinylidene fluoride, styrene butadiene rubber, styrene-isoprene-styrene, and polyacrylate.

8. The positive electrode plate according to any one of claims 3 to 7, a negative electrode plate and a separator, The separator is located between the negative electrode plate and the positive electrode plate.

9. 9. The battery of claim 8, wherein the negative plate has a negative active material, the width of the negative active material being greater than the width of the positive active material, and an edge of the negative active material extending to the insulating adhesive.

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