Preparation method of lithium battery pole piece and lithium battery pole piece

Abstract

The invention discloses a preparation method of a lithium battery pole piece and the lithium battery pole piece, and the preparation method comprises the following steps: respectively manufacturing coating layers on two sides of a porous foil to form a pole piece material; in the area, corresponding to the non-hole-opening area of the porous foil, of the coating layer, an infiltration channel is cleaned out through laser; and slitting the pole piece material subjected to laser cleaning to form a plurality of pole pieces. According to the invention, the infiltration channel is cleaned only by using laser instead of cleaning the surface of the coating layer in a large area, so that the energy density of the pole piece can be prevented from being influenced by a relatively large cleaning area, and the electrolyte infiltration efficiency and the energy density of the pole piece are balanced. Therefore, the lithium battery pole piece which is high in infiltration efficiency, light in weight and high in energy density can be obtained based on the method.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for preparing a lithium battery pole piece and a lithium battery pole piece. Background Art

[0002] Lithium-ion batteries, as an important energy storage device, are widely used in portable electronic devices, electric vehicles, and other fields. Improving the energy density and cycle performance of lithium-ion batteries is a long-standing goal within the industry. Currently, increasing the thickness of the positive and negative electrodes and the active material loading can effectively increase the battery's energy density. However, as the electrode thickness increases, the electrolyte's infiltration efficiency within the electrode decreases significantly, leading to problems such as reduced discharge capacity and increased internal resistance.

[0003] To improve the electrolyte's wetting efficiency within the electrode, existing technologies employ a variety of measures, including optimizing electrode structure and modifying separators. Among these, porous foil, due to its porous structure, can improve electrolyte wetting efficiency while also offering the advantage of lightweighting. However, the wetting efficiency of non-perforated areas of porous foil is roughly the same as that of conventional foil. Laser cleaning of the electrode surface can effectively improve electrolyte wetting efficiency, but cleaning the entire electrode surface reduces the battery's energy density, and dust generated during the laser cleaning process can also contaminate the electrode.

[0004] Therefore, while existing technologies improve the electrolyte infiltration efficiency, they also have problems such as reduced energy density and electrode contamination. A new technical solution is urgently needed to balance the contradiction between electrolyte infiltration efficiency and battery energy density, so as to obtain lithium battery electrodes with high infiltration efficiency, lightweight and high energy density. Summary of the Invention

[0005] The purpose of the present application is to provide a method for preparing a lithium battery pole piece and a lithium battery pole piece, so that the lithium battery pole piece can have the advantages of high infiltration efficiency, light weight and high energy density.

[0006] To achieve the above objectives, the present application provides a method for preparing a lithium battery electrode, comprising the following steps:

[0007] Coating layers are formed on both sides of the porous foil to form a pole sheet material;

[0008] In an area of the coating layer corresponding to a non-opening area of the porous foil, a wetting channel is cleaned by laser;

[0009] The pole piece material after laser cleaning is cut into a plurality of pole pieces.

[0010] Optionally, after forming the coating layers on both sides of the porous foil and before using laser to clean out the infiltration channels, the preparation method further comprises: rolling the electrode sheet material; or,

[0011] After the infiltration channel is cleaned out by laser and before the pole sheet material cleaned by laser is cut, the preparation method further includes: a step of rolling the pole sheet material.

[0012] Optionally, the opening diameter of the porous foil is 0.3-1.0 mm, and the width of the infiltration channel is 0.1-0.2 mm.

[0013] Optionally, the wetting channels are evenly distributed in an area of the coating layer corresponding to a non-opening area of the porous foil and the area ratio does not exceed 1%.

[0014] Optionally, the power range of the laser is 15 to 30 watts, the cleaning speed of the laser is 200 to 500 mm / s, and the spot diameter of the laser is 20 to 50 microns.

[0015] Optionally, the laser cleaning equipment uses the two vertical sides of the pole piece or pole piece material as the X axis and the Y axis, and uses a continuous laser cleaning mode for cleaning;

[0016] When the continuous laser cleaning mode is used for cleaning, laser shielding is performed at positions corresponding to the openings of the porous foil.

[0017] Optionally, while the laser is used to clean out the infiltration channel, a dust removal device is used to remove dust generated during the cleaning process.

[0018] To achieve the above objectives, the present application also provides a method for preparing a lithium battery electrode, comprising the following steps:

[0019] Coating layers are applied on both sides of the porous foil to form a pole sheet material;

[0020] Cutting the electrode sheet material into a plurality of electrode sheets;

[0021] In the area of the coating layer of the pole piece corresponding to the non-opening area of the porous foil, a wetting channel is cleaned by laser.

[0022] Optionally, after forming the pole sheet material and before cutting the pole sheet material into a plurality of pole sheets, the preparation method further comprises: a step of rolling the pole sheet material.

[0023] Optionally, the opening diameter of the porous foil is 0.3-1.0 mm, and the width of the infiltration channel is 0.1-0.2 mm.

[0024] Optionally, the wetting channels are evenly distributed in an area of the coating layer corresponding to a non-opening area of the porous foil and the area ratio does not exceed 1%.

[0025] Optionally, the power range of the laser is 15 to 30 watts, the cleaning speed of the laser is 200 to 500 mm / s, and the spot diameter of the laser is 20 to 50 microns.

[0026] Optionally, the laser cleaning equipment uses the two vertical sides of the pole piece or pole piece material as the X axis and the Y axis, and uses a continuous laser cleaning mode for cleaning;

[0027] When the continuous laser cleaning mode is used for cleaning, laser shielding is performed at positions corresponding to the openings of the porous foil.

[0028] Optionally, while the laser is used to clean out the infiltration channel, a dust removal device is used to remove dust generated during the cleaning process.

[0029] To achieve the above objectives, the present application also provides a lithium battery electrode, comprising:

[0030] A porous foil having a plurality of openings formed thereon;

[0031] The coating layer is coated on both sides of the porous foil, and the area of the coating layer corresponding to the non-opening area of the porous foil is cleaned by laser to form an infiltration channel.

[0032] In the embodiment of the present application, a porous foil is used as the substrate for forming the electrode. In this way, the porous structure of the porous foil can be used to improve the infiltration efficiency of the electrolyte, and it is also beneficial to the lightweight of the product. On this basis, the present embodiment further uses a laser to clean out the infiltration channel in the area of the coating layer corresponding to the non-perforated area of the porous foil, which can improve the overall infiltration efficiency of the non-perforated area of the electrode. Moreover, since only the infiltration channel is cleaned out by laser instead of cleaning the surface of the coating layer on a large area, it can avoid affecting the energy density of the electrode due to the large cleaning area, thereby achieving a balance between the electrolyte infiltration efficiency and the electrode energy density. It can be seen that based on the embodiment of the present application, a lithium battery electrode with high infiltration efficiency, light weight and high energy density can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of the method for preparing a lithium battery electrode in Example 1 of the present application.

[0034] Figure 2 It is a structural schematic diagram of the porous foil in Example 1 of the present application.

[0035] Figure 3 is Figure 2Schematic diagram of the structure of the electrode material formed after coating the coating layer on the porous foil.

[0036] Figure 4 is Figure 3 Schematic diagram of the structure after the infiltration channel is cleaned out of the electrode material.

[0037] Figure 5 It will Figure 4 Schematic diagram of the structure of the electrode formed by cutting the electrode material.

[0038] Figure 6 This is a flow chart of the method for preparing a lithium battery electrode in Example 2 of the present application.

[0039] Figure 7 It is a schematic structural diagram of the porous foil in Example 2 of the present application.

[0040] Figure 8 is Figure 7 Schematic diagram of the structure of the electrode material formed after coating the coating layer on the porous foil.

[0041] Figure 9 It will Figure 8 Schematic diagram of the structure of the electrode formed by cutting the electrode material.

[0042] Figure 10 is Figure 9 Schematic diagram of the structure after the infiltration channel is cleaned out on the electrode.

[0043] Figure 11 yes Figure 10 Schematic diagram of the structure of the porous foil of the middle electrode. DETAILED DESCRIPTION

[0044] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0045] Example 1

[0046] See also Figures 1 to 5 This embodiment discloses a method for preparing a lithium battery electrode 100, comprising the following steps:

[0047] S11 , forming coating layers 2 on both sides of the porous foil 1 to form a pole sheet material 200 .

[0048] S12, laser cleaning is used to form the wetting channels 22 in the area 21 of the coating layer 2 corresponding to the non-perforated area 11 of the porous foil 1. That is, the wetting channels 22 are cleaned on both sides of the non-perforated area of the electrode sheet 200.

[0049] After the porous foil 1 is coated, the openings 12 of the porous foil 1 will be covered ( Figures 3 to 5 as well as Figures 8 to 10 The covered opening 12 area is marked with a dotted line), but since the positions of the openings 12 of the porous foil 1 are arranged in a fixed pattern, this embodiment can refer to the coating edge of the electrode sheet material 200 to determine the non-opening area of the electrode sheet material 200, that is, to determine the area 21 of the coating layer 2 corresponding to the non-opening area 11 of the porous foil 1.

[0050] Specifically, the wetting channels 22 on the coating layer 2 do not penetrate the coating layer 2. Since the wetting channels 22 on the coating layer 2 do not penetrate the coating layer 2, the porous foil 1 will not be exposed at the wetting channels 22.

[0051] S13 , cutting the laser-cleaned pole piece material 200 into a plurality of pole pieces 100 .

[0052] After being cut into a plurality of pole pieces 100 , the pole pieces 100 can be used to prepare lithium batteries.

[0053] In this embodiment, a porous foil 1 is used as the base material for forming the pole piece 100. In this way, the porous structure of the porous foil 1 can be used to improve the infiltration efficiency of the electrolyte, and it is also beneficial to the lightweight of the product. On this basis, this embodiment further uses a laser to clean out an infiltration channel 22 in the area 21 of the coating layer 2 corresponding to the non-perforated area 11 of the porous foil 1, which can improve the overall infiltration efficiency of the non-perforated area of the pole piece 100. Moreover, since only the infiltration channel 22 is cleaned out by laser instead of cleaning a large area of the surface of the coating layer 2, it can avoid affecting the energy density of the pole piece 100 due to the large cleaning area, thereby achieving a balance between the electrolyte infiltration efficiency and the energy density of the pole piece 100. It can be seen that the preparation method based on this embodiment can obtain a lithium battery pole piece 100 with high infiltration efficiency, lightweight and high energy density.

[0054] In some embodiments, after the coating layers 2 are formed on both sides of the porous foil 1 and before the infiltration channels 22 are cleaned out by laser, the preparation method further comprises: a step of rolling the electrode sheet material 200 .

[0055] In some embodiments, after the infiltration channel 22 is cleaned by laser and before the pole sheet material 200 cleaned by laser is cut, the preparation method further includes: a step of rolling the pole sheet material 200 .

[0056] Thus, this embodiment does not limit when the rolling step is performed; it can be performed before or after the laser cleaning of the infiltration channel 22. In other words, the step of using the laser to clean the infiltration channel 22 is independent of whether the rolling step has been performed, as long as the coating step has been completed, and can be determined based on actual debugging conditions.

[0057] In some embodiments, the diameter of the opening 12 of the porous foil 1 is 0.3-1.0 mm, and the width of the infiltration channel 22 is 0.1-0.2 mm. It should be noted that the infiltration channel 22 is not limited to a specific shape or path.

[0058] In some embodiments, the wetting channels 22 are evenly distributed in the area 21 of the coating layer 2 corresponding to the non-perforated area 11 of the porous foil 1 and occupy no more than 1% of the area. Thus, the cleaning area occupies a very small area of the surface of the electrode 100, while promoting the wetting efficiency, and substantially does not affect the energy density of the electrode 100.

[0059] Specifically, the cleaning area and depth of the infiltration channel 22 may be determined according to actual debugging conditions and surface density / energy density requirements, and are not specifically limited in this application.

[0060] In some embodiments, the laser has a power ranging from 15 to 30 watts.

[0061] In some embodiments, the laser cleaning speed is 200-500 mm / s.

[0062] In some embodiments, the spot diameter of the laser is 20 to 50 microns.

[0063] In some embodiments, the laser cleaning device uses the two vertical sides of the pole sheet material 200 as the X-axis and the Y-axis and performs cleaning in a continuous laser cleaning mode.

[0064] Specifically, when using the continuous laser cleaning mode for cleaning, laser shielding is performed at the positions corresponding to the openings 12 of the porous foil 1. Since laser shielding is performed at the positions corresponding to the openings 12 of the porous foil 1, the continuous laser cleaning mode can be used to complete laser cleaning in one go, thereby improving cleaning efficiency.

[0065] More specifically, shielding can be performed by setting a shielding array, and each shielding point can just cover the position corresponding to the opening 12. Of course, it is not limited to this, as long as the position corresponding to the opening 12 can be covered.

[0066] Of course, during laser cleaning, it is not limited to the continuous laser cleaning mode, as long as the purpose of cleaning the infiltration channel 22 that meets the requirements can be achieved.

[0067] In some embodiments, while laser cleaning is performed to form the infiltration channel 22, a dust removal device is used to remove dust generated during the cleaning process. Since the dust generated during the cleaning process is removed by the dust removal device while laser cleaning is performed to form the infiltration channel 22, dust generated during the cleaning process can be prevented from contaminating the pole piece 100.

[0068] Example 2

[0069] See also Figures 6 to 10 This embodiment discloses a method for preparing a lithium battery electrode 100, comprising the following steps:

[0070] S21 , forming coating layers 2 on both sides of the porous foil 1 to form a pole piece material 200 .

[0071] S22 , cutting the electrode sheet material 200 into a plurality of electrode sheets 100 .

[0072] S23 , laser cleaning is used to form a wetting channel 22 in the area 21 of the coating layer 2 of the electrode 100 corresponding to the non-opening area 11 of the porous foil 1 .

[0073] After the porous foil 1 is coated, the openings 12 of the porous foil 1 will be covered ( Figures 3 to 5 as well as Figures 8 to 10 The covered opening 12 area is marked with a dotted line). However, since the positions of the openings 12 of the porous foil 1 are arranged in a fixed pattern, this embodiment can refer to the cutting edge of the electrode 100 to determine the non-opening area of the electrode 100, that is, to determine the area 21 of the coating layer 2 corresponding to the non-opening area 11 of the porous foil 1.

[0074] Specifically, the wetting channels 22 on the coating layer 2 do not penetrate the coating layer 2. Since the wetting channels 22 on the coating layer 2 do not penetrate the coating layer 2, the porous foil 1 will not be exposed at the wetting channels 22.

[0075] After the pole piece 100 is laser cleaned, it can be used in the preparation of lithium batteries.

[0076] In this embodiment, a porous foil 1 is used as the base material for forming the pole piece 100. In this way, the porous structure of the porous foil 1 can be used to improve the infiltration efficiency of the electrolyte, and it is also beneficial to the lightweight of the product. On this basis, this embodiment further uses a laser to clean out an infiltration channel 22 in the area 21 of the coating layer 2 corresponding to the non-perforated area 11 of the porous foil 1, which can improve the overall infiltration efficiency of the non-perforated area of the pole piece 100. Moreover, since only the infiltration channel 22 is cleaned out by laser instead of cleaning a large area of the surface of the coating layer 2, it can avoid affecting the energy density of the pole piece 100 due to the large cleaning area, thereby achieving a balance between the electrolyte infiltration efficiency and the energy density of the pole piece 100. It can be seen that the preparation method based on this embodiment can obtain a lithium battery pole piece 100 with high infiltration efficiency, lightweight and high energy density.

[0077] In some embodiments, after forming the pole sheet material 200 and before cutting the pole sheet material 200 into a plurality of pole sheets 100 , the preparation method further includes: a step of rolling the pole sheet material 200 .

[0078] In some embodiments, the diameter of the opening 12 of the porous foil 1 is 0.3-1.0 mm, and the width of the infiltration channel 22 is 0.1-0.2 mm. It should be noted that the infiltration channel 22 is not limited to a specific shape or path.

[0079] In some embodiments, the wetting channels 22 are evenly distributed in the area 21 of the coating layer 2 corresponding to the non-opening area 11 of the porous foil 1 and the area occupies no more than 1%, that is, the cleaning area occupies a very small area of the surface of the electrode 100, while promoting the wetting efficiency, it basically does not affect the energy density of the electrode 100.

[0080] Specifically, the cleaning area and depth of the infiltration channel 22 may be determined according to actual debugging conditions and surface density / energy density requirements, and are not specifically limited in this application.

[0081] In some embodiments, the laser has a power ranging from 15 to 30 watts.

[0082] In some embodiments, the laser cleaning speed is 200-500 mm / s.

[0083] In some embodiments, the spot diameter of the laser is 20 to 50 microns.

[0084] In some embodiments, the laser cleaning device uses the two vertical sides of the pole piece 100 as the X-axis and the Y-axis and performs cleaning in a continuous laser cleaning mode.

[0085] Specifically, when using the continuous laser cleaning mode for cleaning, laser shielding is performed at the positions corresponding to the openings 12 of the porous foil 1. Since laser shielding is performed at the positions corresponding to the openings 12 of the porous foil 1, the continuous laser cleaning mode can be used to complete laser cleaning in one go, thereby improving cleaning efficiency.

[0086] More specifically, shielding can be performed by setting a shielding array, and each shielding point can just cover the position corresponding to the opening 12. Of course, it is not limited to this, as long as the position corresponding to the opening 12 can be covered.

[0087] Of course, during laser cleaning, it is not limited to the continuous laser cleaning mode, as long as the purpose of cleaning the infiltration channel 22 that meets the requirements can be achieved.

[0088] In some embodiments, while laser cleaning is performed to form the infiltration channel 22, a dust removal device is used to remove dust generated during the cleaning process. Since the dust generated during the cleaning process is removed by the dust removal device while laser cleaning is performed to form the infiltration channel 22, dust generated during the cleaning process can be prevented from contaminating the pole piece 100.

[0089] Example 3

[0090] See also Figure 10 and Figure 11 This embodiment discloses a lithium battery electrode 100, comprising a porous foil 1 and a coating layer 2 applied to both sides of the porous foil 1. The porous foil 1 has a plurality of openings 12 formed therein (forming a porous structure). Regions 21 of the coating layer 2 corresponding to the non-opening regions 11 of the porous foil 1 are laser cleaned to create wetting channels 22.

[0091] In this embodiment, a porous foil 1 is used as the base material for forming the electrode 100. In this way, the porous structure of the porous foil 1 can be used to improve the infiltration efficiency of the electrolyte, and it is also beneficial to the lightweight of the product. On this basis, this embodiment further uses a laser to clean out an infiltration channel 22 in the area 21 of the coating layer 2 corresponding to the non-perforated area 11 of the porous foil 1, which can improve the overall infiltration efficiency of the non-perforated area 11 of the electrode 100. Moreover, since only the infiltration channel 22 is cleaned out by laser instead of cleaning a large area of the surface of the coating layer 2, it can avoid affecting the energy density of the electrode 100 due to the large cleaning area, thereby achieving a balance between the electrolyte infiltration efficiency and the energy density of the electrode 100. It can be seen that the electrode 100 based on this embodiment has the advantages of high infiltration efficiency, lightweight and high energy density.

[0092] In some embodiments, the diameter of the opening 12 of the porous foil 1 is 0.3-1.0 mm, and the width of the infiltration channel 22 is 0.1-0.2 mm. It should be noted that the infiltration channel 22 is not limited to a specific shape or path.

[0093] In some embodiments, the wetting channels 22 on the coating layer 2 do not penetrate the coating layer 2. Since the wetting channels 22 on the coating layer 2 do not penetrate the coating layer 2, the porous foil 1 is not exposed at the wetting channels 22.

[0094] Specifically, the cleaning area and depth of the infiltration channel 22 may be determined according to actual debugging conditions and surface density / energy density requirements, and are not specifically limited in this application.

[0095] It should be noted that the technical solutions of the above-mentioned embodiments of the present application can be applied to different surface density ranges of positive electrode sheets and negative electrode sheets, and the process parameters can be determined according to the actual debugging situation.

[0096] The above disclosure is only a preferred example of the present application, and its purpose is to facilitate the understanding and implementation of those skilled in the art. It certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent application of the present application still fall within the scope covered by the present application.

Claims

1. A method for preparing a lithium battery pole piece, characterized in that: The steps include: Coating layers are formed on both sides of the porous foil to form a pole sheet material; In an area of the coating layer corresponding to a non-opening area of the porous foil, a wetting channel is cleaned by laser; The pole piece material after laser cleaning is cut into a plurality of pole pieces.

2. The method for preparing a lithium battery pole piece according to claim 1, wherein: After the coating layers are formed on both sides of the porous foil and before the infiltration channels are cleaned by laser, the preparation method further comprises: rolling the electrode sheet material; or After the infiltration channel is cleaned out by laser and before the pole sheet material cleaned by laser is cut, the preparation method further includes: a step of rolling the pole sheet material.

3. A method for preparing a lithium battery pole piece, characterized in that: The steps include: Coating layers are applied on both sides of the porous foil to form a pole sheet material; Cutting the electrode sheet material into a plurality of electrode sheets; In the area of the coating layer of the pole piece corresponding to the non-opening area of the porous foil, a wetting channel is cleaned by laser.

4. The method for preparing a lithium battery pole piece according to claim 3, characterized in that: After forming the pole sheet material and before cutting the pole sheet material into a plurality of pole sheets, the preparation method further includes: a step of rolling the pole sheet material.

5. The method for preparing a lithium battery pole piece according to claim 1 or 3, characterized in that: The opening diameter of the porous foil is 0.3-1.0 mm, and the width of the infiltration channel is 0.1-0.2 mm.

6. The method for preparing a lithium battery pole piece according to claim 1 or 3, characterized in that: The wetting channels are evenly distributed in the area of the coating layer corresponding to the non-opening area of the porous foil and the area ratio does not exceed 1%.

7. The method for preparing a lithium battery pole piece according to claim 1 or 3, characterized in that: The power range of the laser is 15 to 30 watts, the cleaning speed of the laser is 200 to 500 mm / s, and the spot diameter of the laser is 20 to 50 microns.

8. The method for preparing a lithium battery pole piece according to claim 1 or 3, characterized in that: The laser cleaning equipment uses the two vertical sides of the pole piece or pole piece material as the X-axis and Y-axis, and uses a continuous laser cleaning mode for cleaning; When the continuous laser cleaning mode is used for cleaning, laser shielding is performed at positions corresponding to the openings of the porous foil.

9. The method for preparing a lithium battery pole piece according to claim 1 or 3, characterized in that: While the infiltration channel is cleaned out by laser, dust generated during the cleaning process is removed by a dust removal device.

10. A lithium battery pole piece, characterized in that: include: A porous foil having a plurality of openings formed thereon; The coating layer is coated on both sides of the porous foil, and the area of the coating layer corresponding to the non-opening area of the porous foil is cleaned by laser to form an infiltration channel.

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