Battery pole piece and battery

Abstract

According to the battery pole piece and the battery provided by the utility model, the first layer of holes are formed in the first active material layer, so that the second active material layer penetrates through the second layer of holes of the current collector and is connected with the first active material layer, the pole piece has good wettability, and the adhesiveness of active materials is stronger; the characteristic of high energy density of the thick electrode can be more effectively exerted, so that the performance of the pole piece and the battery is improved. And moreover, the use of foils with holes is avoided, so that the risk of coating strip breakage caused by foil defects can be reduced, the yield is favorably improved, and the cost is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to a battery electrode and a battery. Background Technology

[0002] Lithium-ion batteries mainly consist of a positive electrode, a negative electrode, an electrolyte, and a separator. Li+ ions reversibly intercalate and deintercalate between the positive and negative electrodes through the separator, while the electrolyte serves as the carrier for Li+ transport. To ensure optimal battery performance, the electrolyte must completely wet the positive and negative electrodes and the separator, forming a Li+ conductive path. Insufficient wetting results in a longer ion transport path, hindering the shuttle movement of lithium ions between the positive and negative electrodes. Electrodes not in contact with the electrolyte cannot participate in the battery's electrochemical reactions, and the battery's interface resistance increases, affecting the battery's capacity, rate performance, and lifespan.

[0003] Currently, the two main methods for manufacturing battery cells are winding and stacking. The wettability of wound cells is relatively poor. Firstly, due to structural limitations, the electrolyte can only penetrate from bottom to top. Secondly, to achieve a compact structure, hot pressing is usually used to compress the cells. Both of these methods affect the wettability of the electrode sheets and restrict the performance of the battery.

[0004] As battery performance requirements become increasingly stringent, thicker electrodes have become the mainstream trend. However, the increase in electrode thickness restricts the electrolyte's ability to wet the electrode and also affects the electrode's peel strength. Utility Model Content

[0005] Therefore, it is necessary to provide a battery electrode and a battery to address the aforementioned technical problems.

[0006] A method for manufacturing battery electrode sheets includes:

[0007] First active material layer, current collector, and second active material layer;

[0008] The first active material layer is disposed on the first side of the current collector, and the second active material layer is disposed on the second side of the current collector, with the first and second sides of the current collector facing away from each other;

[0009] The first active material layer has a plurality of first layer holes, and the current collector has a plurality of second layer holes. Each first layer hole is aligned with and communicates with a second layer hole. The second active material layer includes a second layer body and a plurality of connecting parts. The second layer body is disposed on the second surface of the current collector. Each connecting part protrudes from the side of the second layer body facing the current collector, and each connecting part is inserted into each second layer hole in a corresponding manner. Each connecting part at least partially protrudes to the first surface of the current collector and connects with the first active material layer.

[0010] In one embodiment, a plurality of recessed structures are provided on the surface of the second active material layer, wherein each of the recessed structures does not penetrate the second active material layer.

[0011] In one embodiment, the recessed structure is configured as at least one of the following:

[0012] The recessed structure is a third layer of holes, and each of the third layer holes is a blind hole;

[0013] The recessed structure is a strip-shaped groove;

[0014] The recessed structure is a U-shaped groove or an annular groove.

[0015] In one embodiment, the pore size of each of the third layer pores is 10–80 μm.

[0016] In one embodiment, the spacing between adjacent third layer holes is 1 to 10 mm.

[0017] In one embodiment, the depth of each of the third layer pores is 30–90 μm.

[0018] In one embodiment, each of the third layer holes is aligned with each of the second layer holes.

[0019] In one embodiment, the pore size of each of the first layer pores is 10–80 μm.

[0020] In one embodiment, the spacing between adjacent holes in the first layer is 1 to 10 mm.

[0021] A battery comprising the battery electrode sheets described in the above embodiments.

[0022] The aforementioned battery electrode and battery, by forming a first layer of pores on the first active material layer, allows the second active material layer to penetrate the pores of the current collector and connect with the first active material layer. This gives the electrode both good wettability and stronger adhesion of the active material, enabling more effective utilization of the high energy density characteristics of thick electrodes, thereby improving the performance of the electrode and battery. Furthermore, by avoiding the use of perforated foil, the risk of coating breakage due to foil defects can be reduced, which is beneficial to improving yield and effectively reducing costs. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating a button cell manufacturing method in one embodiment;

[0024] Figure 2 This is a schematic diagram of the process of using laser drilling to drill holes in the first active material layer and the current collector in a coin cell according to one embodiment.

[0025] Figure 3 This is a schematic diagram of the planar structure of the first active material layer and the current collector after drilling in one embodiment;

[0026] Figure 4 This is a schematic diagram of the process of drilling holes in the second active material layer using laser etching in one embodiment;

[0027] Figure 5 This is a schematic cross-sectional view of a battery electrode in one embodiment.

[0028] Explanation of reference numerals in the attached figures:

[0029] 10. Battery electrode; 100. Current collector; 110. First active material layer; 120. Second active material layer; 101. First surface of current collector; 102. Second surface of current collector; 201. First layer hole; 202. Second layer hole; 203. Third layer hole; 510. Laser. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of 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 not intended to limit the scope of this application.

[0031] Example 1

[0032] In this embodiment, as Figure 1 As shown, a method for manufacturing a battery electrode is provided, comprising:

[0033] Step 110: Provide active substance slurry.

[0034] In this embodiment, the active material slurry includes an active material, a conductive agent, a binder, and a dispersant, wherein the ratio of the active material, the conductive agent, the binder, and the dispersant is 96.0:2:1.5:0.5. In this embodiment, the active material slurry is obtained by mixing the active material, the conductive agent, the binder, and the dispersant in a ratio of 96.0:2:1.5:0.5.

[0035] In other embodiments, the active material, conductive agent, binder and dispersant in the active material slurry may also be mixed in other proportions.

[0036] Step 120: Apply an active material slurry to the first surface of the current collector to form a first active material layer on the first surface of the current collector.

[0037] In this embodiment, the current collector is also called foil, such as... Figure 2As shown, the active material slurry is coated on the first surface 101 of the current collector 100 and then dried to form the first active material layer 110.

[0038] Step 130: Drill holes in the first active material layer and the current collector, forming a plurality of first layer holes in the first active material layer and a plurality of second layer holes in the current collector, wherein each first layer hole is aligned with and connected to a second layer hole.

[0039] In this embodiment, as Figure 2 and Figure 3 As shown, perforation technology is used to perforate the first active material layer 110 and the current collector 100. In some embodiments, perforation can be performed from one side of the first active material layer and extend to the current collector, thereby forming a first layer of holes and a second layer of holes that are interconnected on the first active material layer and the current collector, respectively; in some embodiments, perforation can also be performed from the side of the current collector and extend to the first active material layer, thereby forming a first layer of holes 201 and a second layer of holes 202 that are interconnected on the first active material layer and the current collector, respectively.

[0040] Step 140: Apply an active substance slurry to the second surface of the current collector. The active substance slurry enters the first layer pores through the second layer pores to form a second active substance layer on the second surface of the current collector. The second active substance layer passes through the second layer pores and connects with the first active substance layer.

[0041] In this embodiment, an active substance slurry is coated on the second surface of the current collector, and the coated active substance slurry permeates through the second layer pores of the current collector to the first surface of the current collector, connecting with the first active substance layer. The active substance slurry on the second surface is dried to obtain a second active substance layer including a second layer body and multiple connecting parts. The second layer body is disposed on the second surface of the current collector, and each connecting part protrudes from the side of the second layer body facing the current collector. Each connecting part is inserted into each second layer pore in a corresponding manner, and each connecting part at least partially protrudes to the first surface of the current collector and connects with the first active substance layer.

[0042] In this embodiment, when the active material slurry is coated on the second side of the current collector, it penetrates into the first side of the current collector and connects with the first active material layer, so that the second active material layer and the first active material layer can be connected, which plays a role in strengthening the adhesion. This effectively improves the adhesion of the active material layers on the two opposite sides of the current collector.

[0043] Step 150: Etch the second active material layer to form a plurality of recessed structures on the surface of the second active material layer, wherein each of the recessed structures does not penetrate the second active material layer.

[0044] In this embodiment, as Figure 4 As shown, the second active material layer 120 is etched to form a recessed structure on the surface of the second active material layer that does not penetrate the second active material layer, that is, the thickness of the etching is less than the thickness of the second active material layer, thereby preventing the recessed structure from penetrating into the current collector.

[0045] It is worth mentioning that in order to improve the peeling force and wetting performance of the electrode, the existing technology uses perforated foil, that is, the foil is set with perforations. However, there are problems in the production process of this foil. On the one hand, its processing is more difficult and more expensive than ordinary non-perforated foil. On the other hand, because multiple perforations are set on the foil, the foil structure is unstable and prone to defects, and the tape is more likely to break during traction.

[0046] In this application, ordinary unperforated foil is used as the current collector for coating the active material slurry. After the first active material layer is formed on the first side of the current collector, perforation is then performed, thereby replacing the perforated foil used in the prior art. This reduces the risk of coating breakage due to foil defects, which is beneficial to improving yield and effectively reducing costs.

[0047] In addition, in this embodiment, a first layer of pores is formed on the first active material layer and a recessed structure is formed on the second active material layer. This facilitates electrolyte wetting, thereby shortening the standing time after electrolyte injection and improving battery performance.

[0048] It is worth mentioning that the battery electrode in this embodiment is a thick electrode. In the prior art, the thick electrode has a lower peeling force and is more difficult to wet due to the higher amount of auxiliary materials, which are more significant problems. However, in this application, by forming a first layer of pores on the first active material layer and a second layer of pores on the second active material layer, and by allowing the second active material layer to penetrate the second layer of pores of the current collector and connect with the first active material layer, the electrode has both good wettability and stronger adhesion of the active material, which can more effectively utilize the high energy density of the thick electrode, thereby improving the performance of the electrode and the battery.

[0049] In one embodiment, the pore size of each of the first layer pores is 10–80 μm. In this embodiment, the pore size of the first layer pores is equal to that of the second layer pores, and the pore size of each of the second layer pores is 10–80 μm. In this embodiment, setting the pore size of the first layer pores to 10–80 μm can effectively improve the structural stability of the first active material layer and the current collector, and can also effectively improve the adhesion of the active material. It is worth mentioning that if the pore sizes of the first and second layer pores are too small, the connection between the first and second active material layers will not be tight enough, and the adhesion of the active material and the peeling force will not be effectively improved. On the other hand, if the pore sizes of the first and second layer pores are too large, the structure of the first active material layer and the current collector will be unstable. Therefore, in this embodiment, setting the pore size of the first and second layer pores to 10–80 μm can not only effectively improve the adhesion of the active material and the peeling force of the electrode, but also effectively improve the structural stability of the first active material layer and the current collector.

[0050] In one embodiment, the spacing between adjacent first-layer pores is 1–10 mm. In this embodiment, the spacing between second-layer pores is equal to the spacing between first-layer pores, for example, the spacing between second-layer pores is 1–10 mm. It should be understood that if the spacing between the first-layer pores and the second-layer pores is too large, it is not conducive to the connection between the second active material layer and the first active material layer, making the connection unstable and unable to effectively improve adhesion. If the spacing between the first-layer pores and the second-layer pores is too small, the pores become too dense, making the current collector and the first active material layer structure unstable. Therefore, in this embodiment, setting the spacing between the first-layer pores and the second-layer pores to 1–10 mm can effectively avoid the inability to form an effective connection force due to excessive spacing, thus avoiding the inability to form an effective adhesion force. Furthermore, it can also avoid the instability of the current collector and the first active material layer structure due to excessive pore density.

[0051] In one embodiment, the recessed structure is configured as at least one of the following: the recessed structure is a third layer hole, and each of the third layer holes is a blind hole; the recessed structure is a strip groove; the recessed structure is a square groove or an annular groove.

[0052] In this embodiment, the recessed structure serves to reduce the local thickness of the second active material layer, thereby facilitating electrolyte wetting. This recessed structure can be a blind hole, a linear groove, or a U-shaped or annular groove.

[0053] In one embodiment, such as Figure 4 As shown, the recessed structure is a third-layer hole 203, and each of the third-layer holes is a blind hole. In this embodiment, the recessed structure is set as a third-layer hole of blind holes.

[0054] In one embodiment, the pore size of each of the third layer pores is 10–80 μm. In this embodiment, setting the pore size of the second layer pores to 10–80 μm can effectively improve the structural stability of the second active material layer and improve the wetting effect of the electrolyte. It should be understood that if the pore size of the third layer pores is too small, the wettability of the electrode cannot be effectively improved, while if the pore size of the third layer pores is too large, the structure of the second active material layer will be unstable. Therefore, in this embodiment, setting the pore size of the third layer pores to 10–80 μm can not only effectively improve the wettability of the electrode, but also effectively improve the structural stability of the second active material layer.

[0055] In one embodiment, the depth of each of the third-layer pores is 30–90 μm. It should be understood that if the depth of the third-layer pores is too small, the wettability of the electrode cannot be effectively improved; conversely, if the depth of the third-layer pores is too large, the structure of the second active material layer becomes unstable. Therefore, in this embodiment, the pore size of the third layer is set to 30–90 μm, which not only effectively improves the wettability of the electrode but also effectively improves the structural stability of the second active material layer.

[0056] In one embodiment, the spacing between adjacent third-layer pores is 1–10 mm. In this embodiment, setting the spacing between the third-layer pores to 1–10 mm improves the wetting effect of the electrolyte and avoids instability in the structure of the second active material layer due to excessive pore density.

[0057] In one embodiment, each of the third layer holes is aligned with each of the second layer holes. In this embodiment, each third layer hole is aligned with a second layer hole and a first layer hole. Since the third layer holes are blind holes, they are not connected to the second and first layer holes, resulting in a reduction in the local thickness of the electrode and a better wetting effect of the electrolyte.

[0058] In one embodiment, the step of drilling holes in the first active material layer and the current collector to form a plurality of first-layer pores in the first active material layer and a plurality of second-layer pores in the current collector includes:

[0059] A laser is emitted from the side of the first active material layer away from the current collector towards the first active material layer and the current collector, creating holes in the first active material layer and the current collector, forming multiple first-layer holes in the first active material layer and multiple second-layer holes in the current collector.

[0060] In this embodiment, as Figure 2As shown, using laser head 510, laser drilling technology is used to drill holes in the first active material layer 110 and the current collector 100. Specifically, holes are drilled in the first active material layer 110 on the side away from the current collector 100, and the holes penetrate to the current collector 100, thus piercing through the first active material layer 110 and the current collector 100, forming through holes in the first active material layer and the current collector. Multiple first-layer holes 201 are formed in the first active material layer 110, and multiple second-layer holes 202 are formed in the current collector 100.

[0061] In one embodiment, the step of etching the second active material layer to form a plurality of third-layer holes on the surface of the second active material layer includes: etching the second active material layer using a laser, wherein the etching depth is less than the thickness of the second active material layer, to form a plurality of the recessed structures on the surface of the second active material layer.

[0062] In this embodiment, as Figure 4 As shown, laser head 510 is used to etch and drill holes in the second active material layer 120 using laser etching technology. The etching depth is less than the thickness of the second active material layer, so that the formed recessed structure cannot penetrate the second active material layer. This effectively improves the wettability of the electrolyte to the electrode.

[0063] In one embodiment, in the step of coating the first surface of the current collector with an active material slurry, the density of the coated active material slurry is 120 g / m³. 2 ;

[0064] In one embodiment, in the step of coating the second surface of the current collector with an active material slurry, the density of the active material slurry is 120 g / m³. 2 .

[0065] In this embodiment, the density of the active material slurry coated on the surface of the current collector is 120 g / m³. 2 This helps to improve the wetting effect of the electrolyte.

[0066] In other embodiments, the active material slurry may be coated with other densities, which will not be described in detail here.

[0067] Example 2

[0068] In this embodiment, as Figure 5 As shown, a battery electrode 10 is provided, including: a first active material layer 110, a current collector 100, and a second active material layer 120;

[0069] The first active material layer 110 is disposed on the first surface of the current collector 100, and the second active material layer 120 is disposed on the second surface of the current collector 100, with the first and second surfaces of the current collector 100 being disposed opposite to each other;

[0070] The first active material layer 110 has a plurality of first layer holes 201, and the current collector 100 has a plurality of second layer holes 202. Each first layer hole 201 is aligned with and communicates with a second layer hole 202. The second active material layer 120 includes a second layer body and a plurality of connecting portions. The second layer body is disposed on the second surface of the current collector 100. Each connecting portion protrudes from the side of the second layer body facing the current collector 100, and each connecting portion is inserted into each second layer hole 202 in a corresponding manner. Each connecting portion at least partially protrudes to the first surface of the current collector 100 and connects with the first active material layer 110.

[0071] In this embodiment, the second active material layer 120 passes through the second layer hole 202 and connects with the first active material layer 110, which makes the adhesion of the active material stronger and effectively improves the peeling force of the battery electrode 10, resulting in better performance of the battery electrode 10.

[0072] In addition, the connecting part protrudes from the second layer hole 202 to the first surface of the current collector 100 and is inserted into the first layer hole 201 to close the first layer hole 201. In some embodiments, the length of the connecting part inserted into the first layer hole 201 is less than the depth of the first layer hole 201, thereby making the first layer hole 201 form a blind hole structure, so that the electrode has good wettability.

[0073] In one embodiment, a plurality of recessed structures are formed on the surface of the second active material layer 120, wherein each of the recessed structures does not penetrate the second active material layer 120.

[0074] It is worth mentioning that the battery electrode 10 in this embodiment is a thick electrode. In the prior art, the thick electrode has a higher amount of auxiliary materials, resulting in lower peeling force and difficulty in wetting, which are more significant problems. However, in this application, by forming a first layer hole 201 on the first active material layer 110 and forming a recessed structure on the second active material layer 120, and by allowing the second active material layer 120 to penetrate the second layer hole 202 of the current collector 100 and connect with the first active material layer 110, the electrode has both good wettability and stronger adhesion of the active material, which can more effectively utilize the high energy density of the thick electrode, thereby improving the performance of the electrode and the battery.

[0075] In one embodiment, the recessed structure is configured as at least one of the following: the recessed structure is a third layer hole 203, and each of the third layer holes 203 is a blind hole; the recessed structure is a strip groove; the recessed structure is a square groove or an annular groove.

[0076] In this embodiment, the recessed structure serves to reduce the local thickness of the second active material layer 120, thereby facilitating electrolyte wetting. This recessed structure can be a blind hole, a linear groove, or a U-shaped or annular groove.

[0077] In one embodiment, the recessed structure is a third-layer hole 203, and each of the third-layer holes 203 is a blind hole. In this embodiment, the recessed structure is set as a third-layer hole 203 of a blind hole.

[0078] In this embodiment, a first layer of pores 201 is formed on the first active material layer 110, and a third layer of pores 203 is formed on the second active material layer 120. This facilitates electrolyte wetting, thereby shortening the standing time after electrolyte injection and improving battery performance.

[0079] In one embodiment, the pore size of each of the first layer pores 201 is 10–80 μm. In this embodiment, the pore size of the first layer pores 201 is equal to the pore size of the second layer pores 202, and the pore size of each of the second layer pores 202 is 10–80 μm. In this embodiment, setting the pore size of the first layer pores 201 to 10–80 μm can effectively improve the structural stability of the first active material layer 110 and the current collector 100, and can also effectively improve the adhesion of the active material. It is worth mentioning that if the pore sizes of the first layer pores 201 and the second layer pores 202 are too small, the connection between the first active material layer 110 and the second active material layer 120 will not be tight enough, and the adhesion of the active material and the peeling force will not be effectively improved. On the other hand, if the pore sizes of the first layer pores 201 and the second layer pores 202 are too large, the structure of the first active material layer 110 and the current collector 100 will be unstable. Therefore, in this embodiment, the pore size of the first layer pore 201 and the second layer pore 202 is set to 10-80 μm, which can not only effectively improve the adhesion of the active material and the peeling force of the electrode, but also effectively improve the structural stability of the first active material layer 110 and the current collector 100.

[0080] In one embodiment, the spacing between adjacent first layer holes 201 is 1–10 mm. In this embodiment, the spacing between second layer holes 202 is equal to the spacing between first layer holes 201, for example, the spacing between second layer holes 202 is 1–10 mm. It should be understood that if the spacing between first layer holes 201 and second layer holes 202 is too large, it will be detrimental to the connection between the second active material layer 120 and the first active material layer 110, making the connection unstable and unable to effectively improve adhesion. If the spacing between first layer holes 201 and second layer holes 202 is too small, the holes will be too dense, making the current collector 100 and the first active material layer 110 structurally unstable. Therefore, in this embodiment, setting the spacing between first layer holes 201 and the spacing between second layer holes 202 to 1–10 mm can effectively avoid the inability to form an effective connection force due to excessive spacing, thus avoiding the inability to form an effective adhesion force. Furthermore, it can also avoid the instability of the current collector 100 and the first active material layer 110 structurally due to excessive pore density.

[0081] In one embodiment, the pore size of each of the third layer pores 203 is 10–80 μm. In this embodiment, setting the pore size of the second layer pores 202 to 10–80 μm can effectively improve the structural stability of the second active material layer 120 and improve the wetting effect of the electrolyte. It should be understood that if the pore size of the third layer pores 203 is too small, the wettability of the electrode cannot be effectively improved, while if the pore size of the third layer pores 203 is too large, the structure of the second active material layer 120 will be unstable. Therefore, in this embodiment, setting the pore size of the third layer pores 203 to 10–80 μm can not only effectively improve the wettability of the electrode, but also effectively improve the structural stability of the second active material layer 120.

[0082] In one embodiment, the depth of each of the third-layer pores 203 is 30–90 μm. It should be understood that if the depth of the third-layer pores 203 is too small, the wettability of the electrode cannot be effectively improved; conversely, if the depth of the third-layer pores 203 is too large, the structure of the second active material layer 120 becomes unstable. Therefore, in this embodiment, the pore size of the third-layer pores 203 is set to 30–90 μm, which not only effectively improves the wettability of the electrode but also effectively improves the structural stability of the second active material layer 120.

[0083] In one embodiment, the depth of each of the third-layer pores 203 is 30–90 μm. It should be understood that if the depth of the third-layer pores 203 is too small, the wettability of the electrode cannot be effectively improved; conversely, if the depth of the third-layer pores 203 is too large, the structure of the second active material layer 120 becomes unstable. Therefore, in this embodiment, the pore size of the third-layer pores 203 is set to 30–90 μm, which not only effectively improves the wettability of the electrode but also effectively improves the structural stability of the second active material layer 120.

[0084] In one embodiment, the spacing between adjacent third-layer pores 203 is 1–10 mm. In this embodiment, setting the spacing between the third-layer pores 203 to 1–10 mm can improve the wetting effect of the electrolyte and also avoid the instability of the second active material layer 120 structure due to excessive pore density.

[0085] In one embodiment, each of the third layer holes 203 is aligned with each of the second layer holes 202. In this embodiment, each third layer hole 203 is aligned with a second layer hole 202 and a first layer hole 201. Since the third layer hole 203 is a blind hole, it is not connected to the second layer hole 202 and the first layer hole 201, which reduces the local thickness of the electrode and improves the wetting effect of the electrolyte.

[0086] Example 3

[0087] In this embodiment, a battery is provided, including the battery electrode sheets described in any of the above embodiments.

[0088] Example 4

[0089] In this embodiment, the processes for manufacturing battery electrodes and manufacturing the battery are as follows:

[0090] 1. Slurry preparation: The slurry is prepared by means of a certain ratio, such as: active substance: conductive agent: binder: dispersant = 96.0:2:1.5:0.5, but is not limited to this formula.

[0091] 2. A-side coating: Use the above slurry and ordinary foil to coat the surface at a certain density, such as 120g / m2, but not limited to this density. After coating the A-side, dry it.

[0092] 3. Laser drilling: A laser is used to drill holes in a single-sided electrode sheet. The hole diameter is 10-80μm and the spacing between each hole is 1-10mm. The laser directly penetrates the electrode sheet to form continuous and dense holes. It should be noted that the hole spacing needs to be adjusted according to the actual processing to ensure tensile strength.

[0093] 4. B-side coating: For the perforated single-sided electrode, B-side coating is applied. The coating material on B-side can penetrate through the small holes to A-side, which can enhance the adhesion. Conventional coating method and drying are sufficient.

[0094] 5. Laser etching: After coating the B-side, laser etching is performed, but it does not penetrate the foil. The etching depth is lower than the coating thickness, the aperture is 10-80μm, and the spacing between each hole is 1-10mm. The etching is not limited to hole structures, but can also be linear, zigzag, etc.

[0095] 6. After the electrode sheets are etched, they are rolled and processed normally to form batteries through winding or stacking. Subsequent processes are no different from the current mainstream manufacturing process.

[0096] In the above embodiments, the method for manufacturing battery electrodes can be summarized as follows: coating an active material slurry on the A side of the current collector → laser drilling → coating an active material slurry on the B side of the current collector → laser etching. This method does not require the use of a perforated current collector, achieves the desired effect, and improves the reliability of processing and the wettability of the electrode. A significant feature is that the position of the A-face hole is highly consistent with the position of the current collector perforation.

[0097] In this embodiment, the battery made using this method has better liquid retention performance, and the negative electrode sheet made using this method has better adhesion and better suppression of expansion.

[0098] Furthermore, extending this electrode manufacturing method to coating applications for thick electrodes can better leverage the advantages of this method.

[0099] Performance parameter comparison:

[0100] This section compares the electrode peeling force and electrolyte diffusion time of battery electrodes manufactured in the experimental group and the control group. The experimental group was manufactured using the battery electrode manufacturing method described in the above embodiments, while the control group was manufactured using conventional methods. The comparison results are shown in Tables 1 and 2.

[0101] Table 1 Comparison of electrode peeling force between experimental group and control group

[0102]

[0103] Table 2 Comparison of electrolyte diffusion time between experimental group and control group

[0104]

[0105] As can be seen from the above experimental and control groups, the electrode sheet manufactured by the above-mentioned battery electrode sheet manufacturing method of this application has a significantly improved peel force compared with the control group, and the adhesion of the active material is stronger.

[0106] In addition, the experimental group formed a second layer of pores with blind holes on the second active material layer, which made the electrode have good wettability and the electrolyte diffusion time was significantly reduced compared with the control group.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery electrode, characterized in that, include: First active material layer, current collector, and second active material layer; The first active material layer is disposed on the first side of the current collector, and the second active material layer is disposed on the second side of the current collector, with the first and second sides of the current collector facing away from each other; The first active material layer has a plurality of first layer holes, and the current collector has a plurality of second layer holes. Each first layer hole is aligned with and communicates with a second layer hole. The second active material layer includes a second layer body and a plurality of connecting parts. The second layer body is disposed on the second surface of the current collector. Each connecting part protrudes from the side of the second layer body facing the current collector, and each connecting part is inserted into each second layer hole in a corresponding manner. Each connecting part at least partially protrudes to the first surface of the current collector and connects with the first active material layer.

2. The battery electrode according to claim 1, characterized in that, The surface of the second active material layer is provided with a plurality of recessed structures, wherein each of the recessed structures does not penetrate the second active material layer.

3. The battery electrode according to claim 2, characterized in that, The recessed structure is configured as at least one of the following: The recessed structure is a third layer of holes, and each of the third layer holes is a blind hole; The recessed structure is a strip-shaped groove; The recessed structure is a U-shaped groove or an annular groove.

4. The battery electrode according to claim 3, characterized in that, The pore diameter of each of the third layer pores is 10–80 μm.

5. The battery electrode according to claim 3, characterized in that, The spacing between adjacent holes in the third layer is 1 to 10 mm.

6. The battery electrode according to claim 3, characterized in that, The depth of each of the third layer pores is 30–90 μm.

7. The battery electrode according to claim 3, characterized in that, Each of the third layer holes is aligned with each of the second layer holes.

8. The battery electrode according to any one of claims 1-5, characterized in that, The pore size of each of the first layer pores is 10–80 μm.

9. The battery electrode according to any one of claims 1-5, characterized in that, The spacing between adjacent holes in the first layer is 1 to 10 mm.

10. A battery, characterized in that, Includes the battery electrode as described in any one of claims 1-9.

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