Battery pole piece and battery

Abstract

The utility model discloses a battery pole piece and a battery, and relates to the technical field of batteries. The battery pole piece comprises a current collector, an insulating material layer and an active material layer, wherein the insulating material layer and the active material layer are positioned on the surface of the current collector; the insulating material layer has a first orthographic projection on the surface of the current collector, the active material layer has a second orthographic projection on the surface of the current collector, and at least one part of the first orthographic projection is located outside the second orthographic projection. According to the battery pole piece and the battery disclosed by the invention, the risk of peeling of the active material layer caused by cutting of the lead lugs is reduced, and excellent energy storage performance of the battery is ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery electrode and a battery. Background Technology

[0002] Due to their advantages such as high energy density, long cycle life, no memory effect, and environmental friendliness, batteries are widely used in portable electronic products, energy storage devices, and new energy vehicles.

[0003] In related technologies, a battery includes electrodes and a separator. The electrodes include a current collector and an active material layer coated on the surface of the current collector. To enable electron transfer between the battery's internal and external circuits, leads are typically cut into the uncoated foil areas of the current collector. However, during the lead-cutting process, the die-cutting tool can easily cut into the active material layer on the current collector, causing the active material layer to peel off, resulting in waste of active material and a reduction in the battery's energy storage performance. Utility Model Content

[0004] In view of this, this application provides a battery electrode and a battery that reduces the risk of active material layer peeling caused by cutting the leads and ensures excellent energy storage performance of the battery.

[0005] The specific technical solution adopted in this application is as follows:

[0006] The first aspect of this application provides a battery electrode, the battery electrode including a current collector, and an insulating material layer and an active material layer located on the surface of the current collector;

[0007] The insulating material layer has a first orthographic projection on the surface of the current collector, and the active material layer has a second orthographic projection on the surface of the current collector, with at least a portion of the first orthographic projection located outside the second orthographic projection.

[0008] Optionally, the active material layer is located at the middle position of the current collector surface, and the active material layer and the two first edges of the current collector surface are respectively spaced apart, and the two first edges of the current collector surface are opposite each other in the length direction of the battery electrode.

[0009] At least a portion of the insulating material layer is located between the side of the active material layer and the first edge adjacent to the side.

[0010] Optionally, the insulating material layer has a first gap with the adjacent first edge;

[0011] Along the length of the battery electrode, the distance of the first interval is greater than the length of the insulating material layer.

[0012] Optionally, a second gap exists between the insulating material layer and the active material layer;

[0013] Along the length of the battery electrode, the distance of the second interval is smaller than the distance of the first interval.

[0014] Optionally, the distance of the second interval is 0.3-1 mm.

[0015] Optionally, the insulating material layer is adjacent to the active material layer.

[0016] Optionally, the insulating material layer includes a first portion and a second portion connected along the length direction of the battery electrode, the first portion covering the surface of the current collector, and the second portion covering the surface of the active material layer away from the current collector.

[0017] Optionally, along the length direction of the battery electrode, the length of the first portion is greater than or equal to the length of the second portion.

[0018] Optionally, the insulating material layer is a ceramic material layer.

[0019] Optionally, the battery electrode has a tab, which includes at least a portion of the insulating material layer.

[0020] A second aspect of this application provides a battery, the battery including the battery electrodes described in the first aspect.

[0021] In the battery electrode provided in this embodiment, in addition to the active material layer, an insulating material layer is also provided on the surface of the current collector. This insulating material layer may be spaced apart from the active material layer, or only a portion of the insulating material layer may be in contact with the active material layer. Therefore, when cutting the leads of the battery electrode, the cutting trajectory of the leads can be positioned according to the location of the insulating material layer. For example, cutting the portion of the insulating material layer away from the active material layer reduces the risk of cutting the active material layer, thus lowering the risk of peeling off and avoiding waste of the active material. When this battery electrode is applied to a battery, it can improve the battery's energy storage performance. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the surface structure of a battery electrode provided in an embodiment of this application;

[0024] Figure 2 It is along Figure 1 A schematic diagram of the cross-sectional structure obtained by cutting along line AA in the middle;

[0025] Figure 3 This is a schematic diagram of the surface structure of another battery electrode provided in an embodiment of this application;

[0026] Figure 4 It is along Figure 3 A schematic diagram of a cross-sectional structure obtained by cutting along the BB line;

[0027] Figure 5 It is along Figure 3 A schematic diagram of another cross-sectional structure obtained by cutting along the BB line.

[0028] Figure label:

[0029] 1. Current collector; 11. First edge; 12. Second edge; 13. First gap;

[0030] 2. Insulating material layer; 21. Second spacer; 22. First part; 23. Second part;

[0031] 3. Active material layer; 31. Side.

[0032] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0036] This application provides a battery electrode sheet for use in batteries, such as lithium-ion stacked batteries. Figure 1 and Figure 3 These are schematic diagrams of two possible structures for the battery electrode. For example... Figure 1 and Figure 3 As shown, the battery electrode includes a current collector 1, and an insulating material layer 2 and an active material layer 3 located on the surface of the current collector 1. The insulating material layer 2 has a first orthographic projection on the surface of the current collector 1, and the active material layer 3 has a second orthographic projection on the surface of the current collector 1. At least a portion of the first orthographic projection is located outside the second orthographic projection.

[0037] In the battery electrode provided in this embodiment, in addition to the active material layer 3, an insulating material layer 2 is also provided on the surface of the current collector 1. This insulating material layer 2 may be spaced apart from the active material layer 3, or only a portion of the insulating material layer 2 may be in contact with the active material layer 3. Therefore, when cutting the leads of the battery electrode, the cutting trajectory of the leads can be positioned according to the position of the insulating material layer 2. For example, cutting the portion of the insulating material layer 2 away from the active material layer 3 reduces the risk of cutting the active material layer, thus lowering the risk of peeling off and avoiding waste of the active material. When this battery electrode is applied to a battery, it can improve the battery's energy storage performance.

[0038] Furthermore, since the die-cutting blades for cutting the leads are typically made of metal, and the current collector 1 is also made of metal, burrs are easily generated at the cutting point when cutting the leads of the battery electrodes. These burrs may puncture the battery separator, leading to a short circuit. By providing an insulating material layer 2 on the surface of the current collector 1 and using the insulating material layer 2 to position the cutting trajectory of the die-cutting blade, allowing the die-cutting blade to directly cut the insulating material layer 2, the formation of burrs can be avoided, thereby reducing the risk of a short circuit.

[0039] In other words, the battery electrode provided in this application embodiment has a lead, which is obtained by cutting the current collector 1 and the insulating material layer 2 on the battery electrode. Therefore, the lead includes a portion of the current collector 1 and at least a portion of the insulating material layer 2.

[0040] The battery electrode provided in this application embodiment may be, for example, the positive electrode of a battery.

[0041] In this case, the current collector 1 is a positive current collector 1, such as copper foil or aluminum foil. The active material layer 3 can be formed by spraying or coating a positive active material onto the current collector 1, wherein the positive active material can be made from a positive active substance, binder, conductive agent, and solvent in a certain proportion. The insulating material layer 2 can be formed by spraying or coating an insulating material onto the current collector 1, wherein the insulating material has good adhesion to the current collector 1 to ensure reliable connection between it and the surface of the current collector 1. Optionally, the insulating material also has good adhesion to the active material layer 3 to ensure reliable connection between it and the surface of the active material layer 3.

[0042] The thickness of the insulating material layer 2 can be greater than, equal to or less than the thickness of the active material layer 3, and this application does not limit this.

[0043] In some embodiments of this application, the insulating material layer 2 may be a ceramic material layer.

[0044] The ceramic material has excellent adhesion to the current collector 1, ensuring a reliable bond on the surface of the current collector 1 and preventing it from easily detaching. Moreover, the ceramic material itself has the characteristics of good insulation and property stability, as well as low cost.

[0045] During the charging and discharging process of a battery, taking a lithium-ion stacked battery as an example, the active material in the active material layer 3 is used to store and release lithium ions, thereby realizing the storage and release of electrical energy. In order to improve the energy density of the battery, the active material layer 3 covers most of the surface of the current collector 1.

[0046] In some embodiments of this application, the active material layer 3 is located in the middle part of the surface of the current collector 1, and the active material layer 3 and the two first edges 11 of the surface of the current collector 1 are respectively spaced apart, and the two first edges 11 of the surface of the current collector 1 are opposite to each other in the length direction of the battery electrode.

[0047] It should be noted that "the active material layer 3 and the two first edges 11 of the surface of the current collector 1 are respectively spaced apart" means that the active material layer 3 and the two first edges 11 of the surface of the current collector 1 are not adjacent, but "spaced apart" does not refer to a specific distance. That is to say, as Figure 1 As shown, one side of the active material layer 3 is spaced from a first edge 11 adjacent to the surface of the current collector 1, and the other side of the active material layer 3 is spaced from another first edge 11 adjacent to the surface of the current collector 1. However, the distances between the two sides of the active material layer 3 and the corresponding first edges 11 may be equal or unequal.

[0048] By creating a gap between the active material layer 3 and the two first edges 11 on the surface of the current collector 1, a cutting area for the lead is reserved. After the lead is cut out, the electronic transmission and transfer between the internal and external circuits of the battery can be easily realized.

[0049] Optionally, the current collector 1 surface has two opposing second edges 12 along the width direction of the battery electrode. The active material layer 3 extends to the two second edges 12 on both sides of the current collector 1 surface in the width direction of the battery electrode, thereby maximizing the energy density of the battery.

[0050] like Figures 1 to 5 As shown, at least a portion of the insulating material layer 2 is located between the side 31 of the active material layer 3 and the first edge 11 adjacent to the side 31.

[0051] For example, such as Figures 1 to 5 As shown, there can be two insulating material layers 2, with the two insulating material layers 2 located on opposite sides of the active material layer 3 along the length of the battery electrode. Furthermore, at least a portion of each insulating material layer 2 is located on the side of the active material layer 3 closest to the adjacent first edge 11.

[0052] In this way, no matter which side of the active material layer 3 is cut, the cutting trajectory of the lead can be located according to the position of the insulating material layer 2, thereby reducing the risk of cutting the active material layer and causing it to peel off, thus avoiding the waste of active material to a certain extent.

[0053] In some embodiments of this application, such as Figures 1 to 5 As shown, the insulating material layer 2 has a first gap 13 between it and the adjacent first edge 11. Furthermore, along the length direction of the battery electrode, the distance of the first gap 13 is greater than the length of the insulating material layer 2.

[0054] For areas on the surface of current collector 1 where no active material layer 3 is formed (hereinafter referred to as "empty foil areas"), the insulating material layer 2 does not completely cover the empty foil areas, but is only formed in a part of the empty foil areas, thus avoiding waste of insulating material and saving more.

[0055] In some embodiments of this application, such as Figure 1 and Figure 2 As shown, a second gap 21 may be present between the insulating material layer 2 and the active material layer 3. Furthermore, along the length direction of the battery electrode, the distance of the second gap 21 is less than the distance of the first gap 13.

[0056] By setting a gap between the insulating material layer 2 and the active material layer 3, the die-cutting tool can be further away from the active material layer 3 when cutting the lead ears. As a result, the die-cutting tool is less likely to cut the active material layer 3 during the cutting of the lead ears along the insulating material layer 2, which reduces the risk of active material falling off and the probability of impurities falling into the stack core, thereby reducing the risk of battery short circuit.

[0057] Since the distance of the second interval 21 is smaller than the distance of the first interval 13, the cut-out tabs are larger in size along the length of the battery electrode, thus having sufficient structural strength and avoiding breakage during subsequent folding or use.

[0058] Optionally, the distance of the second interval 21 is 0.3-1mm. Within this range, the coating boundary of the insulating material and the active material can be easily controlled, preventing cross-contamination when the insulating material and the active material are coated simultaneously. This improves the dimensional accuracy of the coating of the insulating material and the active material, and also improves the coating efficiency because the two material layers can be coated simultaneously.

[0059] Optionally, the distance of the second interval 21 is 0.5 mm. After multiple tests, it was found that when the distance of the second interval 21 is 0.5 mm, the coating boundary of the insulating material (especially the ceramic material) can be controlled more accurately, and cross-contamination when the insulating material and the active material are coated at the same time can be completely avoided.

[0060] In some embodiments of this application, such as Figure 3 and Figure 4 As shown, the insulating material layer 2 is adjacent to the active material layer 3.

[0061] In this case, when coating the insulating material layer 2 and the active material layer 3, these two material layers can be coated sequentially. For example, the active material layer 3 can be coated first, and after the active material layer 3 has been formed and cured, the insulating material layer 2 can be coated. This avoids cross-contamination between the insulating and active materials. At this time, the position of the insulating material layer 2 can still be used to locate the cutting trajectory of the lead, thereby preventing the die-cutting tool from cutting the active material layer 3 when cutting the lead.

[0062] In some embodiments of this application, such as Figure 3 and Figure 5 As shown, a portion of the insulating material layer 2 can also cover the side of the active material layer 3 away from the current collector 1, thereby achieving a stacked arrangement of the two.

[0063] For example, such as Figure 5 As shown, the insulating material layer 2 includes a first part 22 and a second part 23 connected along the length direction of the battery electrode. The first part 22 covers the surface of the current collector 1, and the second part 23 covers the surface of the active material layer 3 away from the current collector 1.

[0064] When cutting the leads of the battery electrode, if the die-cutting tool accidentally cuts the active material layer 3, the insulating material layer 2 can wrap around the active material because the insulating material layer 2 covers the active material layer 3 and is also connected to the current collector 1. This prevents the active material from falling off the current collector 1, reduces the waste of active material, and ensures the high energy density of the battery electrode.

[0065] Optionally, such as Figure 5 As shown, along the length direction of the battery electrode, the length of the first part 22 is greater than or equal to the length of the second part 23.

[0066] In this way, when using a die-cutting tool to cut the lead ears, the die-cutting tool has a larger working space on the first part 22, which improves the tolerance of the cutting trajectory of the die-cutting tool to a certain extent and avoids it from cutting the active material layer 3.

[0067] A second aspect of this application provides a battery comprising the electrodes described in the first aspect. Exemplarily, the battery may be a lithium-ion laminated battery.

[0068] The battery provided in this application embodiment has high energy density and achieves excellent energy storage performance because it uses the battery electrode sheet described in the above embodiment; in addition, the insulating material layer 2 on the battery electrode sheet also reduces the risk of short circuit caused by die-cutting burrs, and the safety performance is also improved.

[0069] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0070] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery electrode, characterized in that, The battery electrode includes a current collector (1), and an insulating material layer (2) and an active material layer (3) located on the surface of the current collector (1); The insulating material layer (2) has a first orthographic projection on the surface of the current collector (1), and the active material layer (3) has a second orthographic projection on the surface of the current collector (1), with at least a portion of the first orthographic projection located outside the second orthographic projection.

2. The battery electrode according to claim 1, characterized in that, The active material layer (3) is located in the middle of the surface of the current collector (1), and the active material layer (3) and the two first edges (11) of the surface of the current collector (1) are respectively spaced apart, and the two first edges (11) of the surface of the current collector (1) are opposite to each other in the length direction of the battery electrode. At least a portion of the insulating material layer (2) is located between the side (31) of the active material layer (3) and the first edge (11) adjacent to the side (31).

3. The battery electrode according to claim 2, characterized in that, The insulating material layer (2) has a first gap (13) between it and the adjacent first edge (11); Along the length of the battery electrode, the distance of the first interval (13) is greater than the length of the insulating material layer (2).

4. The battery electrode according to claim 3, characterized in that, There is a second gap (21) between the insulating material layer (2) and the active material layer (3); Along the length of the battery electrode, the distance of the second interval (21) is less than the distance of the first interval (13).

5. The battery electrode according to claim 4, characterized in that, The distance of the second interval (21) is 0.3-1mm.

6. The battery electrode according to any one of claims 1-3, characterized in that, The insulating material layer (2) is adjacent to the active material layer (3).

7. The battery electrode according to any one of claims 1-3, characterized in that, The insulating material layer (2) includes a first part (22) and a second part (23) connected along the length direction of the battery electrode. The first part (22) covers the surface of the current collector (1), and the second part (23) covers the surface of the active material layer (3) away from the current collector (1).

8. The battery electrode according to claim 7, characterized in that, Along the length direction of the battery electrode, the length of the first part (22) is greater than or equal to the length of the second part (23).

9. The battery electrode according to any one of claims 1-3, characterized in that, The insulating material layer (2) is a ceramic material layer.

10. The battery electrode according to any one of claims 1-3, characterized in that, The battery electrode has a tab, which includes at least a portion of the insulating material layer (2).

11. A battery, characterized in that, The battery includes the battery electrode as described in any one of claims 1-10.

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