Pole piece, battery cell, battery and etching device for etching pole piece

Abstract

The utility model discloses an electrode plate, electric core, battery and etching equipment for etching electrode plate, the electrode plate includes current collector and sets up in the active material layer of current collector one side or both sides, the active material layer is on the width direction interval of electrode plate and is provided with a plurality of line grooves, each line groove extends along the length direction of electrode plate, the more close to the center area of electrode plate in the width direction, the smaller spacing between two adjacent line grooves, and the depth of at least one line groove of the center area of the width direction of electrode plate is greater than the depth of the line groove of both sides. The scheme greatly reduces the number of line grooves, thereby reducing the light emitting frequency of laser, and further is favorable for improving production efficiency and etching precision and reducing manufacturing cost, and because the light emitting frequency of laser is reduced, the scheme can reduce the error rate of scribe spacing, and the scheme also adjusts the spacing between two adjacent line grooves, and realizes the purpose of improving the infiltration degree of electrolyte while maintaining high energy density.

Description

Technical Field

[0001] This utility model relates to the technical field of batteries, and in particular to an electrode sheet, a battery cell, a battery, and an etching device for etching the electrode sheet. Background Technology

[0002] As consumer electronics demand increasingly higher battery energy density, the active material coating on the electrodes in current batteries is becoming thicker and its compaction density is increasing. This makes electrolyte wetting more difficult and electrolyte retention lower, significantly hindering ion transport within the electrodes. To address this issue, please refer to [link to relevant documentation]. Figure 1 Existing technologies mostly use lasers to scribing lines on the surface of the active material layer of the electrode 1 to form grooves 13, thereby increasing the ability of ions to transport within the electrode 1. However, currently, the scribing direction Y of the grooves 13 is perpendicular to the length direction X of the electrode, resulting in a large number of grooves 13 and a large number of laser beams, which reduces scribing efficiency and increases manufacturing costs. In addition, multiple scribing operations increase the error rate (the scribing spacing is prone to deviating from the normal value), which to some extent increases the risk of battery manufacturing. Furthermore, currently, multiple grooves 13 are set at equal intervals, and the electrolyte wetting degree still needs further improvement. Utility Model Content

[0003] This utility model provides an electrode sheet, a battery cell, a battery, and an etching device for etching the electrode sheet, which mainly solves the technical problems of low efficiency, easy error, high cost, and low electrolyte wetting degree of current electrode sheet scribing.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] An electrode includes a current collector and an active material layer disposed on one or both sides of the current collector. The active material layer has multiple grooves spaced apart in the width direction of the electrode, and each groove extends along the length direction of the electrode.

[0006] The closer to the center region of the electrode in the width direction, the smaller the spacing between two adjacent grooves; and the depth of at least one groove in the center region of the electrode in the width direction is greater than the depth of the grooves on both sides.

[0007] In one of the technical solutions, five grooves are provided on the active material layer, and the five grooves are sequentially arranged as a first groove, a second groove, a third groove, a fourth groove, and a fifth groove along the width direction of the electrode sheet.

[0008] The distance between the first and second grooves is A, the distance between the second and third grooves is B, the distance between the third and fourth grooves is C, and the distance between the fourth and fifth grooves is D. A is greater than B, D is greater than C, the third groove has the greatest depth, the depth of the first groove is less than the depth of the second groove, the depths of the second and fourth grooves are both less than the depth of the third groove, and the depth of the fifth groove is less than the depth of the fourth groove.

[0009] In one of the technical solutions, the width E of the electrode is 50mm-90mm, A and D are both 2mm-4mm, and B and C are both 1mm-2mm.

[0010] In one of the technical solutions, the distance between the first groove and the electrode in the width direction and one of its adjacent edges is F, and the distance between the fifth groove and the electrode in the width direction and one of its adjacent edges is G, where both F and G are 3mm-5mm.

[0011] In one of the technical solutions, the depths of the first groove, the second groove, the third groove, the fourth groove, and the fifth groove all account for 20%-40% of the total thickness of the electrode sheet.

[0012] In one technical solution, the depth of the first groove and the fifth groove is 20%-25% of the total thickness of the electrode sheet, the depth of the second groove and the fourth groove is 30%-35% of the total thickness of the electrode sheet, and the depth of the third groove is 35%-40% of the total thickness of the electrode sheet.

[0013] In one of the technical solutions, the thickness of the active material layer on one side of the current collector is 30-70 μm.

[0014] This application also provides a battery cell, including a positive electrode, a separator, and a negative electrode. The separator is disposed between the positive electrode and the negative electrode. A positive tab is connected to the positive electrode, and a negative tab is connected to the negative electrode. At least one of the positive electrode and the negative electrode adopts the electrode structure described above.

[0015] This application also provides a battery, including a pouch casing and the aforementioned battery cell, wherein the pouch casing encloses the battery cell, and both the positive electrode tab and the negative electrode tab extend outward relative to the pouch casing.

[0016] This application also provides an etching apparatus for etching an electrode sheet, including a fixed base, multiple conveying rollers, and multiple lasers; the multiple conveying rollers are rotatably connected to the fixed base and are used to support the transport of the electrode sheet; the multiple lasers are arranged at adjacent positions on the conveying rollers; the multiple lasers are staggered along the width direction of the electrode sheet; the emitting ends of the multiple lasers are all facing the conveying rollers and are used to etch the grooves on the surface of the electrode sheet.

[0017] Compared with the prior art, the electrode provided by this utility model has at least the following beneficial effects:

[0018] This solution changes the direction of scribing on the electrode from the width direction to the length direction. That is, the multiple grooves formed after scribing on the electrode are changed from being spaced apart along the length direction to being spaced apart along the width direction. This solution can significantly reduce the number of grooves, thereby reducing the number of laser beams, which is conducive to greatly improving production efficiency and etching accuracy, as well as reducing manufacturing costs. Moreover, due to the reduction in the number of laser beams, this solution can reduce the error rate of scribing spacing.

[0019] Furthermore, the most difficult area for electrolyte to wet on the electrode is currently the central region, which is most prone to ion deposition. Current techniques involve adding more grooves in the central region, which improves electrolyte wetting, but this also leads to a loss of active material and lower battery energy density. This solution adjusts the spacing between adjacent grooves, making them smaller as they approach the center of the electrode in the width direction. Additionally, the depth of the grooves in the central region is designed to be greater than that on the sides, allowing for increased electrolyte wetting while maintaining a constant number of grooves. In other words, this solution improves electrolyte wetting without excessive removal of active material, thus achieving both increased wetting and high energy density. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of an electrode sheet with multiple grooves provided in the prior art;

[0022] Figure 2 This is a schematic diagram of the structure of an electrode sheet provided in an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the electrode sheet in the thickness direction provided in an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the structure of a battery provided in an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of an etching apparatus for etching electrodes, provided as an embodiment of this application.

[0027] Figure label:

[0028] 1. Electrode; 11. Current collector; 12. Active material layer; 13. Groove; 131. First groove; 132. Second groove; 133. Third groove; 134. Fourth groove; 135. Fifth groove; 2. Conveyor roller; 3. Laser; 4. Battery cell; 41. Positive tab; 42. Negative tab; 5. Soft-pack outer shell. Detailed Implementation

[0029] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0030] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0031] It should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] Please refer to the following: Figure 2 and Figure 3 This utility model provides an electrode 1, which includes a current collector 11 and an active material layer 12 coated on one or both sides of the current collector 11. The thickness of the active material layer 12 on one side is preferably between 30um and 70um. When the active material layer 12 is a positive electrode slurry, the electrode 1 is understood as a positive electrode. When the active material layer 12 is a negative electrode slurry, the electrode 1 is understood as a negative electrode. In this design, the surface of the active material layer 12 is provided with multiple grooves 13 spaced apart along the width direction Y of the electrode 1. Each groove 13 extends along the length direction X of the electrode 1. In this design, the direction of scribing on the electrode 1 is changed from the width direction Y of the electrode 1 to the length direction X of the electrode 1. That is, in this design, the multiple grooves 13 formed after scribing on the electrode 1 are changed from being spaced apart along the length direction X of the electrode 1 to being spaced apart along the width direction Y of the electrode 1. This design can significantly reduce the number of grooves 13, thereby reducing the number of laser emission times. This is beneficial to significantly improve production efficiency and etching accuracy, as well as reduce manufacturing costs. Moreover, due to the reduction in the number of laser emission times, this design can also reduce the error rate of scribing spacing and improve the production quality of the battery.

[0035] Currently, the most difficult area for the electrolyte to wet on electrode 1 is the central region of electrode 1, where ion deposition is most likely to occur. Current technology involves adding more grooves 13 to the central region of electrode 1. While this improves electrolyte wetting, the increased number of grooves 13 leads to the loss of some active material, resulting in lower battery energy density. Please refer to [the relevant documentation] again for further details. Figure 2 and Figure 3The closer to the center region of the electrode 1 in the width direction Y, the smaller the spacing between two adjacent grooves 13 is designed. Moreover, the depth of at least one groove 13 in the center region of the electrode 1 in the width direction Y is greater than the depth of the other grooves 13 on both sides. By adjusting the spacing between two adjacent grooves 13 and designing the depth of the groove 13 in the center region of the electrode 1 to be greater than the depth of the grooves 13 on both sides, this solution can improve the electrolyte wetting degree while keeping the number of grooves 13 constant. That is, this solution can improve the electrolyte wetting degree without removing too much active material, thereby achieving the goal of maintaining a high energy density while improving the electrolyte wetting degree.

[0036] Please refer to them again. Figure 2 and Figure 3If the number of grooves 13 is too large, too much of the active material layer 12 will be removed, which will reduce the energy density of the battery. If the number of grooves 13 is too small, the electrolyte wetting degree will be insufficient. Therefore, in this embodiment, five grooves 13 are preferably provided on the active material layer 12, and the depth of the five grooves 13 is designed to be 20%-40% of the total thickness of the electrode sheet. For ease of further explanation, in this embodiment, the five grooves 13 are arranged sequentially along the width direction Y of the electrode sheet 1 as the first groove 13. 1. The first groove 131, the second groove 132, the third groove 133, the fourth groove 134, and the fifth groove 135 are defined. Let A be the distance between the first groove 131 and the second groove 132, B be the distance between the second groove 132 and the third groove 133, C be the distance between the third groove 133 and the fourth groove 134, and D be the distance between the fourth groove 134 and the fifth groove 135. Then, A is greater than B, and D is greater than C. Furthermore, the third groove 133 has the greatest depth. Since the width E of the electrode 1 is mostly 50mm-90mm, preferably A and D are both 2mm-4mm, and preferably B and C are both 1mm-2mm. Let F be the distance between the first groove 131 and the electrode 1 along the width direction Y, and G be the distance between the fifth groove 135 and the electrode 1 along the width direction Y, preferably both F and G are 3mm-5mm. More preferably, the depth of the first groove 131 is less than the depth of the second groove 132, the depths of the second groove 132 and the fourth groove 134 are both less than the depth of the third groove 133, and the depth of the fifth groove 135 is less than the depth of the fourth groove 134. This design of the depths of the five grooves 13 allows the depth of the grooves 13 to decrease gradually as they approach the center of the electrode 1, thereby improving the wettability of the electrolyte. Specifically, the depths of the first groove 131 and the fifth groove 135 each account for 20%-25% of the total thickness of the electrode 1, the depths of the second groove 132 and the fourth groove 134 each account for 30%-35% of the total thickness of the electrode 1, and the depth of the third groove 133 accounts for 35%-40% of the total thickness of the electrode.

[0037] Please see Figure 4 This embodiment also provides a battery cell 4, which includes a positive electrode, a negative electrode, and a separator. The separator is disposed between the positive electrode and the negative electrode to prevent the positive electrode and the negative electrode from coming into contact with each other and causing a short circuit. A positive electrode tab 41 is connected to the positive electrode, and a negative electrode tab 42 is connected to the negative electrode. At least one of the positive electrode and the negative electrode adopts the structure of the electrode 1 described above, thereby improving the degree of wetting of the positive electrode or the negative electrode by the electrolyte, and thus improving the performance of the battery cell 4.

[0038] Please see Figure 5This embodiment also provides a battery, which includes a soft-pack casing 5 and the aforementioned battery cell 4. The soft-pack casing 5 is typically made of existing aluminum-plastic film. The soft-pack casing 5 wraps the battery cell 4 and is filled with electrolyte. Furthermore, the positive electrode tab 41 and the negative electrode tab 42 need to be led outward relative to the soft-pack casing 5. Since the battery in this embodiment uses the aforementioned battery cell 4, the battery in this embodiment also has the advantages of high energy density and high electrolyte wetting degree.

[0039] Please see Figure 6 This embodiment also provides an etching apparatus for etching electrode sheets. This etching apparatus can be used before or after baking the electrode sheet 1. The apparatus includes a fixed base (not shown in the figure), multiple conveyor rollers 2, and a laser 3. The multiple conveyor rollers 2 are rotatably connected to the fixed base and are used to support the transport of the electrode sheet 1. During transport, the electrode sheet 1 drives the conveyor rollers 2 to rotate, thereby reducing the friction between the electrode sheet 1 and the conveyor rollers 2 and preventing severe scratching of the electrode sheet 1 when supported by the conveyor rollers 2. The laser 3 is arranged adjacent to the conveyor rollers 2, with the emitting end of the laser 3 facing the conveyor rollers 2. The laser 3 is used to etch the aforementioned grooves 13 onto the surface of the electrode sheet 1. Specifically, this solution utilizes the conveyor rollers 2 to support and transport the electrode sheet 1 while simultaneously etching the grooves 13 along its length. Furthermore, this solution utilizes the speed of the electrode sheet 1's own conveyor belt for etching, which reduces the number of laser emission cycles, allowing the laser 3 to provide stable power output, thus significantly improving production efficiency and etching accuracy. In addition, since the electrode 1 is supported by the conveyor roller 2 when it is etched by the laser 3, the electrode 1 will not vibrate significantly during the etching process, which helps to further improve the etching accuracy of the electrode 1.

[0040] The above are merely preferred embodiments of the present utility model, and only specifically describe the technical principles of the present utility model. These descriptions are only for explaining the principles of the present utility model and should not be construed as limiting the scope of protection of the present utility model in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model, as well as other specific embodiments of the present utility model that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of the present utility model.

Claims

1. A pole piece, characterized in that, It includes a current collector and an active material layer disposed on one or both sides of the current collector. The active material layer has multiple grooves spaced apart in the width direction of the electrode, and each groove extends along the length direction of the electrode. The closer to the center region of the electrode in the width direction, the smaller the spacing between two adjacent grooves; and the depth of at least one groove in the center region of the electrode in the width direction is greater than the depth of the grooves on both sides.

2. The pole piece of claim 1, wherein The active material layer is provided with five grooves, which are arranged sequentially along the width direction of the electrode as the first groove, the second groove, the third groove, the fourth groove and the fifth groove. The distance between the first groove and the second groove is A, the distance between the second groove and the third groove is B, the distance between the third groove and the fourth groove is C, and the distance between the fourth groove and the fifth groove is D. A is greater than B, D is greater than C, and the third groove has the greatest depth.

3. The pole piece of claim 2, wherein The width E of the electrode is 50mm-90mm, A and D are both 2mm-4mm, and B and C are both 1mm-2mm.

4. The pole piece of claim 3, wherein Let F be the distance between the first groove and the electrode in the width direction and its adjacent edge, and let G be the distance between the fifth groove and the electrode in the width direction and its adjacent edge, where both F and G are 3mm-5mm.

5. The pole piece of claim 2, wherein The depths of the first groove, the second groove, the third groove, the fourth groove, and the fifth groove are all 20%-40% of the total thickness of the electrode sheet.

6. The pole piece of claim 5, wherein The depth of the first groove and the fifth groove is 20%-25% of the total thickness of the electrode sheet, the depth of the second groove and the fourth groove is 30%-35% of the total thickness of the electrode sheet, and the depth of the third groove is 35%-40% of the total thickness of the electrode sheet.

7. The electrode sheet as described in claim 5, characterized in that, The thickness of the active material layer on one side of the current collector is 30um-70um.

8. A battery cell, characterized in that, The device includes a positive electrode, a separator, and a negative electrode. The separator is disposed between the positive electrode and the negative electrode. A positive electrode tab is connected to the positive electrode, and a negative electrode tab is connected to the negative electrode. At least one of the positive electrode and the negative electrode adopts the structure of the electrode as described in any one of claims 1 to 7.

9. A battery, characterized in that, It includes a soft-pack casing and the battery cell as described in claim 8, wherein the soft-pack casing encloses the battery cell, and both the positive tab and the negative tab extend outward relative to the soft-pack casing.

10. An etching apparatus for etching electrodes, characterized in that, It includes a fixed base, multiple conveying rollers, and a laser; the multiple conveying rollers are rotatably connected to the fixed base and are used to support the transport of the electrode sheet; the laser is arranged at an adjacent position to the conveying rollers, and the emitting end of the laser is facing the conveying roller and is used to etch the grooves on the surface of the electrode sheet.

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