A method for preparing a lithium battery pole piece

Abstract

The present invention proposes a method for preparing lithium battery pole pieces, comprising the following steps: S1, providing a welding substrate and moving the welding substrate in a predetermined direction, wherein: the welding substrate is provided with multiple coating areas spaced apart along its length, with a non-coating area formed between any two adjacent coating areas; S2, welding a metal foil to the upper and / or lower surfaces of the non-coating area; S3, laser cutting the non-coating area welded with the metal foil into the shape of a pole ear, cutting the welding substrate at the non-coating area to obtain the pole piece, and collecting the pole piece. The present invention utilizes a gap coating method to process the welding substrate, breaking the limitation of battery length size on equipment manufacturing. By controlling the size of the metal foil, pre-cutting it, and using an ultrasonic welding head to absorb and weld the metal foil, the utilization rate of the metal foil can be improved.

Description

Technical Field

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

[0002] Currently, lithium-ion battery pole pieces are typically produced using a continuous coating process, with the tab dimension reserved on one side of the coating substrate. As a lightweight design to improve battery cell performance, a composite current collector is used as the coating substrate to reduce battery weight and increase cell energy density. Because this composite current collector consists of a non-metallic layer coated with a very thin metal material on both sides, a layer of pure metal foil is welded to the upper and lower surfaces of the tab to address strength and overcurrent issues.

[0003] The existing technology is to arrange metal foil coils on the upper and lower layers of the composite substrate respectively, weld the multiple layers of material together using an ultrasonic welding machine through synchronous conveying, and then use a laser to cut the tabs and cut them to complete the production. The traditional method requires that the welded metal foil be a continuous strip material to achieve continuous welding while conveying. After the welding is completed, the part outside the tab needs to be cut off. A large amount of metal foil will be wasted, which is not conducive to reducing manufacturing costs and saving resources. In addition, the traditional method requires that the tab be on one side of the length of the battery cell. For battery cells with a length of more than 500mm, if a longer cantilever structure is used, it will be detrimental to the stability of the equipment; if a double support structure is used, the equipment structure will be too complicated and difficult to manufacture. Summary of the Invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a method for preparing a lithium battery electrode.

[0005] The present invention provides a method for preparing a lithium battery electrode, comprising the following steps:

[0006] S1. Providing a welding substrate and moving the welding substrate in a predetermined direction, wherein: the welding substrate is provided with a plurality of coating areas spaced apart along its length, and a non-coating area is formed between any two adjacent coating areas;

[0007] S2. Welding the metal foil on the upper surface and / or lower surface of the non-coated area;

[0008] S3. Laser cutting the non-coated area where the metal foil is welded into the shape of the pole ear, and cutting the welding substrate at the non-coated area to obtain the pole piece, and collecting the pole piece.

[0009] In a preferred embodiment of the present invention, in step S1 , the length of the coating area is the length of a single pole piece.

[0010] In a preferred embodiment of the present invention, in step S1 , the length of the non-coating area is the length of a single pole piece tab.

[0011] In a preferred embodiment of the present invention, in step S2, the size of the metal foil is not larger than the size of the non-coating area.

[0012] In a preferred embodiment of the present invention, in step S2, a welding station is set on the moving path of the welding substrate, and two ultrasonic welding heads are set at the welding station. The two ultrasonic welding heads are respectively located on the upper and lower sides of the welding substrate, and the ultrasonic welding heads are used to weld the metal foil in the non-coated area of ​​the welding station.

[0013] In a preferred embodiment of the present invention, the ultrasonic welding head has a cylindrical structure and rotates around its central axis. The axial direction of the ultrasonic welding head is perpendicular to the moving direction of the welding substrate. The edge of the ultrasonic welding head is provided with an arc-shaped protrusion coaxial with the head, and a plurality of welding points are distributed around the periphery of the arc-shaped protrusion.

[0014] In a preferred embodiment of the present invention, in step S1, a plurality of adsorption holes are distributed on the periphery of the arc-shaped protrusion, a negative pressure chamber connected to the plurality of adsorption holes is provided in the ultrasonic welding head, and the negative pressure chamber is connected to the vacuum pump through a pipeline.

[0015] In a preferred embodiment of the present invention, a metal foil loading station is provided on the side of the ultrasonic welding head away from the welding substrate. When the arc-shaped protrusion of the ultrasonic welding head rotates to the metal foil loading station, the vacuum pump is started and the ultrasonic welding head absorbs the metal foil; when the arc-shaped protrusion of the ultrasonic welding head rotates to the welding substrate, the vacuum pump is turned off, the metal foil is adhered to the non-coated area, and the welding point welds the metal foil and the welding substrate together.

[0016] In a preferred embodiment of the present invention, in step S3, a negative pressure pipeline is provided to collect waste generated by laser cutting.

[0017] The present invention provides a method for preparing a lithium battery pole piece. The welding substrate is provided with multiple coating areas spaced apart along its length, the coating areas forming a pole piece coating layer, a metal foil is welded to the upper surface and / or lower surface of a non-coating area formed between any two adjacent coating areas, and the non-coating area welded with the metal foil is laser cut to form a pole lug, which is then cut to obtain a pole piece.

[0018] The present invention utilizes a gap coating method to process the welding substrate, breaking the limitation of battery length size on equipment manufacturing. By controlling the size of the metal foil and pre-cutting it, and using an ultrasonic welding head to absorb and weld the metal foil, the utilization rate of the metal foil can be improved, the difficulty of equipment manufacturing caused by the excessive width of the battery cell can be reduced, the efficiency of electrode preparation is improved, and the problems of material waste and low efficiency in the current roll welding method are solved.

[0019] The ultrasonic welding head of the present invention is cylindrical in shape and can rotate synchronously while welding to achieve continuous tape feeding and non-stop welding; the laser cutting process is synchronized with the tape feeding process, which can achieve continuous cutting of multi-layer materials after welding. During cutting, the cut waste can be automatically adsorbed and collected through a negative pressure pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a welding substrate in a method for preparing a lithium battery electrode proposed in the present invention;

[0021] Figure 2 This is a schematic diagram of the arrangement of metal foil on a welding substrate in a method for preparing a lithium battery electrode proposed in the present invention;

[0022] Figure 3 This is a welding principle diagram in a lithium battery electrode preparation method proposed by the present invention;

[0023] Figure 4 This is a schematic structural diagram of an ultrasonic welding head in a method for preparing a lithium battery electrode proposed in the present invention;

[0024] Figure 5 This is a schematic diagram of the metal foil after welding in a method for preparing a lithium battery electrode proposed by the present invention;

[0025] Figure 6 This is a schematic diagram of the laser cutting principle in the lithium battery electrode preparation method proposed in the present invention. DETAILED DESCRIPTION

[0026] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0027] The present invention provides a method for preparing a lithium battery electrode, comprising the following steps:

[0028] S1. Provide a welding substrate 1 and move the welding substrate along a predetermined direction, wherein: Figure 1 As shown, a plurality of coating areas 1-1 are spaced apart along the length direction of the welding substrate 1, and a non-coating area 1-2 is formed between any two adjacent coating areas 1-1;

[0029] Wherein: the length of the coated area 1-1 is the length of a single pole piece, and the length of the non-coated area 1-2 is the length of a single pole piece tab;

[0030] S2, welding the metal foil 2 on the upper surface and the lower surface of the non-coating area 1-2;

[0031] Wherein: the size of the metal foil 2 is not greater than the size of the non-coating area 1-2, and the arrangement of the metal foil 2 on the welding substrate is as follows: Figure 2 As shown;

[0032] Specifically, a welding station is set on the moving path of the welding substrate 1, and two ultrasonic welding heads 3 are set at the welding station. The two ultrasonic welding heads 3 are respectively located on the upper and lower sides of the welding substrate 1. The ultrasonic welding heads 3 are used to weld the metal foil 2 to the non-coated area 1-2 at the welding station;

[0033] Specifically, if Figure 3 、 Figure 4 As shown, the ultrasonic welding head 3 has a cylindrical structure and rotates around its central axis. The axial direction of the ultrasonic welding head 3 is perpendicular to the moving direction of the welding substrate. The edge of the ultrasonic welding head 3 is provided with a coaxial arc-shaped protrusion 3-1. A plurality of welding points 3-2 are distributed on the periphery of the arc-shaped protrusion 3-1. A plurality of adsorption holes 3-3 are also distributed on the periphery of the arc-shaped protrusion 3-11. A negative pressure chamber connected to the plurality of adsorption holes 3-3 is provided in the ultrasonic welding head 3, and the negative pressure chamber is connected to a vacuum pump through a pipeline.

[0034] Specifically, if Figure 3 As shown, a metal foil loading station is provided on the side of the ultrasonic welding head 3 away from the welding substrate 1. When the arc-shaped protrusion 3-2 of the ultrasonic welding head 3 rotates to the metal foil loading station, the vacuum pump is started, and the ultrasonic welding head 3 absorbs the metal foil 2; after rotating 180 degrees, when the arc-shaped protrusion 3-2 of the ultrasonic welding head 3 rotates to the non-coating area 1-2 of the welding substrate 1, the vacuum pump is turned off, and the metal foil 2 is attached to the non-coating area 1-2. The welding point welds the metal foil 2 and the welding substrate 1 together. After the metal foil 2 is welded, Figure 5 As shown;

[0035] S3, laser cutting the non-coated area 1-2 welded with the metal foil 2 into the shape of the pole ear, the laser cutting path can be set according to the product, and the welding base material is cut off at the non-coated area 1-2 to obtain the pole piece (such as Figure 6 As shown), the cut pole pieces can be collected at a designated location for storage; at the same time, a negative pressure pipeline is set to collect the waste generated by laser cutting.

[0036] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a lithium battery pole piece, characterized in that: The following steps are involved: S1. Providing a welding substrate and moving the welding substrate in a predetermined direction, wherein: the welding substrate is provided with a plurality of coating areas spaced apart along its length, and a non-coating area is formed between any two adjacent coating areas; S2. Welding the metal foil on the upper surface and / or lower surface of the non-coated area; S3. Laser cutting the non-coated area where the metal foil is welded into the shape of the pole ear, and cutting the welding substrate at the non-coated area to obtain the pole piece, and collecting the pole piece; In step S2, a welding station is set on the moving path of the welding substrate, and two ultrasonic welding heads are set at the welding station. The two ultrasonic welding heads are respectively located on the upper and lower sides of the welding substrate. The ultrasonic welding heads are used to weld the metal foil in the non-coated area of ​​the welding station; The ultrasonic welding head is cylindrical and rotates around its central axis. The axial direction of the ultrasonic welding head is perpendicular to the moving direction of the welding substrate. The edge of the ultrasonic welding head is provided with an arc-shaped protrusion coaxial with it, and multiple welding points are distributed around the arc-shaped protrusion. In step S1 , a plurality of adsorption holes are distributed on the periphery of the arc-shaped protrusion, a negative pressure chamber communicating with the plurality of adsorption holes is provided in the ultrasonic welding head, and the negative pressure chamber is connected to a vacuum pump through a pipeline.

2. The method for preparing a lithium battery pole piece according to claim 1, characterized in that: In step S1 , the length of the coating area is the length of a single pole piece.

3. The method for preparing a lithium battery pole piece according to claim 1, wherein: In step S1 , the length of the non-coating area is the length of a single pole piece tab.

4. The method for preparing a lithium battery pole piece according to claim 1, characterized in that: In step S2, the size of the metal foil is no larger than the size of the non-coating area.

5. The method for preparing a lithium battery pole piece according to claim 4, characterized in that: A metal foil loading station is provided on the side of the ultrasonic welding head away from the welding substrate. When the arc-shaped protrusion of the ultrasonic welding head rotates to the metal foil loading station, the vacuum pump starts and the ultrasonic welding head absorbs the metal foil; when the arc-shaped protrusion of the ultrasonic welding head rotates to the welding substrate, the vacuum pump is turned off, the metal foil is attached to the non-coated area, and the welding point welds the metal foil and the welding substrate together.

6. The method for preparing a lithium battery pole piece according to any one of claims 1 to 4, characterized in that: In step S3, a negative pressure pipeline is set to collect waste generated by laser cutting.

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