Device for removing passivation layer on surface of lithium-containing strip

Abstract

The utility model discloses a device for removing a passivation layer on the surface of a lithium-containing strip, which comprises a supporting roller component, a supporting roller component and a driving component, the lithium-containing strip driving assembly is used for driving the lithium-containing strip to move around the supporting carrier roller in a manner that one surface with a passivation layer deviates from the supporting carrier roller, and driving the supporting carrier roller to rotate; the brush assembly comprises a driving element and a cylindrical brush parallel to the supporting carrier rollers; and the fine adjustment assembly is used for adjusting the center distance between the cylindrical brush and the supporting carrier roller, so that the cylindrical brush is in contact with the passivation layer on the lithium-containing strip bypassing the supporting carrier roller, and the cylindrical brush is driven by the driving element to rotate to continuously roll and brush the passivation layer, so that the passivation layer on the lithium-containing strip is brushed away. The device can remove various types of passivation layer materials such as lithium oxide and lithium carbonate on the surface of the lithium-containing strip, roll-to-roll batch processing can be achieved, the processing effect is good, the production efficiency is high, and the product consistency is good.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery manufacturing technical field especially relates to a device that removes the passivation layer on the surface of lithium-containing strip. BACKGROUND

[0002] Metal lithium is a rare element, and its density is 0.534 g / cm 3 , which is the lightest metal. Its melting point is 180.54 DEG C, and its boiling point is 1317 DEG C. It has the characteristics of softness, great toughness, good ductility, good chemical activity, high negative potential, large specific energy, and reaction with a large number of inorganic reagents and organic reagents, and very violent reaction with water.

[0003] During production, storage, and transportation, it will react with water vapor, oxygen, carbon dioxide, nitrogen, and other substances in the air, thereby generating a layer of surface passivation layer containing lithium oxide, lithium carbonate, lithium hydroxide, lithium nitride, and other substances on the surface of the lithium-containing strip. These passivation layers or impurities will have adverse effects on the performance of the product when the lithium-containing strip is used in batteries or other process links, so they need to be removed.

[0004] The commonly used passivation layer removal methods currently include chemical solvent reaction method, plasma etching method, etc. However, none of them is suitable for the treatment of the surface passivation layer of the lithium-containing strip. Since metal lithium is extremely active, and the surface passivation layer material is complex and diverse, it is impossible to remove various materials by using the chemical solvent reaction method, and new impurities will also be introduced due to the residual solvent components. Patent CN117711922A and CN116536670A mention the method of using plasma to remove the surface passivation layer. However, even the existing low-temperature plasma technology still has a relatively high temperature, which will still cause the extremely active metal lithium to react with the surrounding gas and introduce new impurities. On the other hand, plasma has a significant effect on removing organic impurities, but it has no obvious effect on removing lithium oxide, lithium carbonate, lithium nitride, and other impurities.

[0005] Therefore, the utility model provides a device for removing the surface passivation layer of a lithium-containing strip, which can precisely control the passivation layer removal depth and surface roughness by precisely controlling the rolling brush depth and rolling brush speed through the mechanical rolling brush method. UTILITY MODEL CONTENTS

[0006] The utility model aims at overcoming the defects in the prior art and providing a device for removing the surface passivation layer of metal lithium, which is simple to operate and reliable.

[0007] The purpose of the utility model can be achieved by the following technical solutions.

[0008] The device for removing the passivation layer on the surface of lithium-containing strip includes a supporting roller assembly, a lithium-containing strip driving assembly, a brush assembly and a fine adjustment assembly. The supporting roller assembly includes a supporting roller and a roller fixing seat. The supporting roller is composed of a supporting shaft, a roller sleeve and a bearing. The roller sleeve is fixedly connected with the supporting shaft through the bearing. After the connection, the roller sleeve can rotate around the supporting shaft. The lithium-containing strip driving assembly drives the lithium-containing strip to move around the supporting roller in such a way that the side with the passivation layer faces away from the supporting roller, and drives the supporting roller to rotate. The brush assembly includes a driving element and a cylindrical brush. The driving element is used to drive the cylindrical brush to rotate. The supporting roller is arranged in parallel with the cylindrical brush. The fine adjustment assembly is used to adjust the center distance between the cylindrical brush and the supporting roller, so that the cylindrical brush is in contact with the passivation layer on the lithium-containing strip moving around the supporting roller. The cylindrical brush rotates under the driving of the driving element to continuously roll and brush the passivation layer, so as to remove the passivation layer on the lithium-containing strip.

[0009] The lithium-containing strip driving assembly can include a lithium-containing strip unwinding device and a winding device. The strip winding and unwinding device can make the strip pass between the supporting roller and the cylindrical brush. When the cylindrical brush rotates, a relative speed difference is generated between the cylindrical brush and the strip, so that the passivation layer on the surface of the strip is removed.

[0010] Suppose the running speed of the lithium-containing strip is v, the diameter of the cylindrical brush is D, and the rotating speed of the cylindrical brush is n. Then, the length of the relative rolling and brushing friction of the cylindrical brush per unit length of the lithium-containing strip is: .

[0011] By adjusting the distance between the cylindrical brush and the supporting roller, the depth of removing the passivation layer on the surface of the lithium-containing strip can be adjusted. The deeper the cylindrical brush is pressed into the lithium-containing strip, the deeper the depth of removing the passivation layer on the surface of the lithium-containing strip.

[0012] By adjusting the softness and hardness of the brush hair of the cylindrical brush, the roughness of the surface of the lithium-containing strip can be controlled. The thinner the diameter of the brush hair, the softer the brush hair, and the longer the length of the relative rolling and brushing friction of the cylindrical brush per unit length of the lithium-containing strip, the smoother the surface of the lithium-containing strip. The thicker the diameter of the brush hair, the harder the brush hair, and the shorter the length of the relative rolling and brushing friction of the cylindrical brush per unit length of the lithium-containing strip, the rougher the surface of the lithium-containing strip.

[0013] Optionally, the brush assembly further includes a power transmission shaft, a shaft coupling, a bearing seat and a positioning center. The driving element is connected with the power transmission shaft through the shaft coupling. The power transmission shaft is rotatably fixed in the bearing seat through the bearing. One end of the cylindrical brush is connected with the power transmission shaft, and the other end is connected with the positioning center.

[0014] Optionally, the end of the power transmission shaft in contact with the cylindrical brush has a positioning center and a transmission pin for transmitting power.

[0015] Optionally, the cylindrical brush is composed of a shaft and soft bristles uniformly distributed on the shaft.

[0016] Optionally, the shaft of the cylindrical brush has positioning holes or positioning surfaces at both ends.

[0017] Optionally, the fine adjustment assembly is composed of a cylinder and a fine adjustment mechanism, which can realize micron-level position adjustment.

[0018] Optionally, the fine adjustment assembly is arranged at both ends of the cylindrical brush, i.e., one end is arranged at the bearing seat of the power transmission shaft, and the other end is arranged at the positioning center; the cylindrical brush can be made close to or away from the supporting roller.

[0019] Optionally, the fine adjustment assembly is arranged at the roller fixing seat at both ends of the supporting roller assembly, so that the supporting roller can be made close to or away from the cylindrical brush.

[0020] Optionally, the working area of the supporting roller and the cylindrical brush is also provided with a dust suction or collection device.

[0021] Optionally, the working environment of the device is an inert gas environment or a low dew point environment.

[0022] The technical scheme of the utility model has at least one of the following advantages:

[0023] 1. The device has wide application range and can remove any type of passivation layer.

[0024] 2. The thickness of the removed passivation layer can be adjusted in microns, and the passivation layer removal thickness can be accurately controlled.

[0025] 3. By controlling the hardness of the bristles and the relative rotating speed of the cylindrical brush, the surface roughness of the lithium-containing strip after removing the passivation layer can be controlled; rough or smooth surface can be obtained according to needs.

[0026] 4. The mechanical rolling brush is used in a roll-to-roll continuous processing mode, which has high production efficiency, stable product quality after processing, and good consistency. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a working principle schematic diagram of the device of the utility model.

[0028] Figure 2 is an isometric side view of the device for removing the passivation layer on the surface of the lithium-containing strip which can be used in the utility model.

[0029] Figure 3 is Figure 2 schematic diagram after removing the dust cover.

[0030] Figure 4 is Figure 3 schematic view of a top view.

[0031] Figure number explanation: 100 lithium-containing strip; 110 passivation layer; L center distance of cylindrical brush and support roller; 200 brush assembly; 210 driving element; 220 bearing seat; 230 power transmission shaft; 240 coupling; 250 transmission pin; 260 positioning center; 270 center fixed seat; 280 center tightening cylinder; 290 cylindrical brush; 300 support roller assembly; 310 support roller; 311 support shaft; 312 roller sleeve; 320 roller fixed seat; 330 adjustable cylinder; 340 fine adjustment assembly; 400 dust collecting cover; 410 dust suction port. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application are described below. It should be understood that other various embodiments can be conceived and modified by those skilled in the art according to the teachings of the present disclosure without departing from the scope or spirit of the present application. Therefore, the following specific embodiments are not limiting in nature.

[0033] In the description of the present application, it should be understood that the terms "upper", "lower", etc. are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation on the present application.

[0034] Reference Figure 1 , Figure 1 As shown in the schematic diagram of the working principle of the device of the present application, the surface of the lithium-containing strip 100 usually reacts with various components in the air due to the relatively active metal lithium to form a passivation layer 110 containing various impurities. Such a complex composition passivation layer usually has an adverse effect during use of the lithium-containing strip, so it needs to be removed during use. In an inert gas environment or a low dew point environment, the lithium-containing strip 100 is passed around the support roller 310, the side of the lithium-containing strip 100 with the passivation layer 110 is arranged opposite to the cylindrical brush 290, the center distance L of the cylindrical brush and the support roller is adjusted, so that the depth of the cylindrical brush 290 pressed into the lithium-containing strip 100 can be adjusted, so that the thickness of the removed passivation layer 100 can be adjusted. When removing the passivation layer 110 on the lithium-containing strip 100, the lithium-containing strip 100 is passed around the support roller 310, the support roller 310 rotates under the driving of the lithium-containing strip 100; the cylindrical brush 290 rotates in the same direction as the support roller 310 under the driving of the driving element, that is, the linear speed direction of the cylindrical brush 290 is opposite to the running direction of the lithium-containing strip 100.

[0035] The device for removing the passivation layer on the surface of the lithium-containing strip will be described in detail below in combination with specific embodiments.

[0036] ReferenceFigures 2-3 The device for removing the passivation layer on the lithium-containing strip includes a brush assembly 200, a supporting roller assembly 300, and a dust collection cover 400.

[0037] The brush assembly 200 is composed of a driving element 210, a bearing seat 220, a power transmission shaft 230, a coupling 240, a transmission pin 250, a positioning center 260, a center fixing seat 270, a centering cylinder 280, and a cylindrical brush 290. The two ends of the cylindrical brush 290 are connected with the power transmission shaft 230 and the positioning center 260, respectively. The cylindrical brush 290 is provided with a groove at least on one end of the power transmission shaft 230, which is matched with the transmission pin 250. The transmission pin 250 is connected with the groove of the cylindrical brush 290 after penetrating the power transmission shaft 230 to realize the transmission of the rotary motion. The power transmission shaft 230 is rotatably fixed with the bearing seat 220 through a bearing (not shown in the figure). One end of the power transmission shaft 230 is connected with the cylindrical brush 290 to transmit power, and the other end is connected with the driving element 210 through the coupling 240. The positioning center 260 at the other end of the cylindrical brush 290 is fixed with the centering cylinder 280 through the center fixing seat 270. The centering cylinder 280 can reciprocate along the axis direction of the cylindrical brush 290. When the centering cylinder 280 moves away from the cylindrical brush 290, the positioning center 260 is separated from the cylindrical brush 290, and the cylindrical brush 290 can be replaced or disassembled at this time. When the centering cylinder 280 moves close to the cylindrical brush 290, the centering cylinder 280 drives the positioning center 260 to tightly press the cylindrical brush 290.

[0038] The supporting roller assembly 300 is composed of a supporting roller 310, a roller fixing seat 320, an adjustable cylinder 330, and a fine adjustment assembly 340. The supporting roller 310 is composed of a supporting shaft 311, a bearing (not shown in the figure), and a roller sleeve 312. The roller sleeve 312 is fixedly connected with the supporting shaft 311 through the bearing, and can realize rotary motion around the axis of the supporting shaft 311. The two ends of the supporting shaft 311 of the supporting roller 310 are fixedly connected with the adjustable cylinder 330 through the roller fixing seat 320. The adjustable cylinder 330 can drive the supporting roller 310 to move close to or away from the brush assembly 200. The adjustable cylinder 330 is further provided with the fine adjustment assembly 340. The fine adjustment assembly 340 can realize micron-level adjustment accuracy, and accurately control or limit the center distance L between the cylindrical brush 290 and the supporting roller 310.

[0039] The dust collection cover 400 covers at least the working area of the cylindrical brush 290 and the supporting roller assembly 300. The dust collection cover 400 is further provided with a dust suction port 410. The dust collection cover 400 is connected with the pipeline (not shown in the figure) of the dust collector through the dust suction port 410, so as to collect the passivation layer powder falling from the roller brush.

[0040] It should be understood that the device for removing the passivation layer on the surface of the lithium-containing strip described in the present application is only a part of the equipment. A complete device for removing the passivation layer on the surface of the lithium-containing strip should also include necessary unwinding assemblies and winding assemblies.

[0041] Reference Figures 1-4 The specific operation process of the device is as follows: first, the preparation work of threading the strip. The lithium-containing strip 100 to be processed is unwound by the unwinding assembly, passes through the support rollers 310 in the support roller assembly 300, and one side of the passivation layer 110 in the lithium-containing strip 100 is away from the support rollers 310. The processed lithium-containing strip 100 is wound by the winding assembly. Then, according to the process parameters such as the thickness and surface roughness of the passivation layer to be removed, the fine adjustment assembly 340 is adjusted to keep the support rollers 310 and the cylindrical brush 290 at a reasonable center distance L between the cylindrical brush and the support rollers. Finally, the equipment is started, and the unwinding assembly, the winding assembly and the device for removing the passivation layer on the surface of the lithium-containing strip all start to operate, and the passivation layer 110 on the lithium-containing strip 100 is removed under the action of the rotating brush of the cylindrical brush 290.

[0042] The device can control the removal depth of the passivation layer 110 on the surface of the lithium-containing strip 100 and the surface roughness of the lithium-containing strip 100 after the passivation layer 110 is removed by setting different strip running speeds, the hardness of the cylindrical brush bristles, the rotating speed of the cylindrical brush, etc.

[0043] Suppose the strip running speed of the lithium-containing strip is v, the diameter of the cylindrical brush is D, and the rotating speed of the cylindrical brush is n, then the length of the cylindrical brush relative to the rolling brush friction per unit length of the lithium-containing strip is: .

[0044] In this embodiment, the diameters of the support rollers 310 and the cylindrical brush 290 are both set to 100mm.

[0045] The surface roughness values of the lithium-containing strip after the passivation layer is removed under different strip running speeds v, cylindrical brush rotating speeds n and cylindrical brush bristle diameters of the lithium-containing strip 100 are shown in Table 1.

[0046] Table 1:

[0047]

[0048] In Table 1, V represents the strip running speed of the lithium-containing strip, n represents the rotating speed of the cylindrical brush, L represents the center distance between the cylindrical brush and the support rollers, d represents the diameter of the cylindrical brush bristles, L' represents the length of the cylindrical brush relative to the rolling brush friction per unit length of the lithium-containing strip obtained by calculation, t represents the thickness of the passivation layer removed from the lithium-containing strip, and Sa represents the surface roughness of the lithium-containing strip after the passivation layer is removed.

[0049] It can be found by comparing Example 1 with Example 3 and Example 6 with Example 8 that the smaller the distance between the cylindrical brush and the supporting backup roll, the deeper the removed passivation layer, and the greater the surface roughness after removing the passivation layer.

[0050] It can be found by comparing Example 1 with Example 2 and Example 6 with Example 7 that the thicker the diameter of the brush hair of the cylindrical brush, the deeper the removed passivation layer, and the greater the surface roughness after removing the passivation layer.

[0051] It can be found by comparing Example 1 with Example 4 and Example 6 with Example 9 that the longer the length of the relative friction of the cylindrical brush to the roll brush per unit length of the lithium-containing strip calculated by the running speed, the brush rotation speed and the brush diameter, the deeper the removed passivation layer, and the smaller the surface roughness after removing the passivation layer.

[0052] It can be found by comparing Example 4 with Example 5 that when other parameters are unchanged, after increasing the running speed, the length of the relative friction of the cylindrical brush to the roll brush per unit length of the lithium-containing strip calculated by the running speed, the brush rotation speed and the brush diameter becomes shorter, the removed passivation layer becomes shallower, and the surface roughness after removing the passivation layer becomes greater.

[0053] It can be found by the above examples that when the center distance L between the cylindrical brush and the supporting backup roll and the brush diameter d are unchanged, the depth of the removed passivation layer is not directly related to the running speed and the rotation speed of the cylindrical brush, but is closely related to the length of the relative friction of the cylindrical brush to the roll brush per unit length of the lithium-containing strip. The longer the length of the relative friction of the cylindrical brush to the roll brush per unit length of the lithium-containing strip, the deeper the removed passivation layer, and at the same time, the smaller the surface roughness after removing the passivation layer, that is, the smoother the surface. The thinner the brush hair diameter, the softer the brush hair; the thicker the brush hair diameter, the harder the brush hair; when other conditions are unchanged, the thicker the brush hair, the deeper the removed passivation layer, and the greater the surface roughness after removing the passivation layer.

[0054] In summary, the thickness t of the removed passivation layer of the lithium-containing strip is positively related to the length L' of the relative friction of the cylindrical brush to the roll brush per unit length of the lithium-containing strip, positively related to the brush hair diameter d, and negatively related to the center distance L between the cylindrical brush and the supporting backup roll. It can be expressed by conversion as t∝L'd / L, and further deduced as t∝nDd / VL. The surface roughness Sa of the lithium-containing strip after removing the passivation layer is negatively related to the length L' of the relative friction of the cylindrical brush to the roll brush per unit length of the lithium-containing strip, positively related to the brush hair diameter d, and negatively related to the center distance L between the cylindrical brush and the supporting backup roll. It can be expressed by conversion as Sa∝d / L'L, and further deduced as Sa∝dV / DnL.

[0055] In actual batch production and application, it is usually required to take a large belt speed V in order to obtain a higher production efficiency. Since the diameter D of the cylindrical brush is basically unchanged after the equipment is finalized, the following conclusions can be drawn:

[0056] If it is required to increase the removal depth of the passivation layer, according to t∝nDd / VL, the rotational speed n of the cylindrical brush can be increased, the brush bristle diameter d can be increased, or the center distance L between the cylindrical brush and the supporting roller can be reduced to achieve the purpose.

[0057] If it is required to reduce the surface roughness Sa, according to Sa∝dV / DnL, the brush bristle diameter d can be reduced (i.e. a softer brush is used), the rotational speed n of the brush can be increased, and the center distance L between the cylindrical brush and the supporting roller can be appropriately increased to achieve the purpose.

[0058] If it is required to ensure the thickness of the removed passivation layer and a small surface roughness at the same time, according to t∝nDd / VL and Sa∝dV / DnL, the rotational speed n of the brush can be increased and the belt speed V can be reduced to achieve the purpose; when the production efficiency is not affected, the rotational speed n of the brush can only be increased to achieve the purpose.

[0059] Although the utility model has been disclosed as above, the utility model is not limited thereto. Any person skilled in the art, without departing from the spirit and scope of the utility model, can make various changes and modifications, and therefore the protection scope of the utility model should be subject to the range defined by the claims.

Claims

1. A device for removing the passivation layer on the surface of lithium-containing strip, comprising: a support roller assembly, which comprises a support backup roll and a backup roll fixing seat, the support backup roll being composed of a support shaft, a roller sleeve and a bearing, the roller sleeve being fixedly connected with the support shaft through the bearing and being capable of rotating around the support shaft; a lithium-containing strip driving assembly, which drives the lithium-containing strip to move around the support backup roll in such a way that the side with the passivation layer faces away from the support backup roll, and drives the support backup roll to rotate; a brush assembly, which comprises a driving element and a cylindrical brush, the driving element being used to drive the cylindrical brush to produce rotational movement; wherein the support backup roll is arranged in parallel with the cylindrical brush; and a fine adjustment assembly, which is used to adjust the center distance between the cylindrical brush and the support backup roll, so that the cylindrical brush is in contact with the passivation layer on the lithium-containing strip moving around the support backup roll, and the cylindrical brush, driven by the driving element, realizes continuous rolling brushing of the passivation layer, thereby brushing off the passivation layer on the lithium-containing strip.

2. The apparatus for removing the surface passivation layer of a lithium-containing strip as claimed in claim 1, wherein, The brush assembly further comprises a power transmission shaft, a shaft coupling, a bearing seat and a positioning center, the driving element being connected with the power transmission shaft through the shaft coupling, the power transmission shaft being rotatably fixed in the bearing seat through the bearing, one end of the cylindrical brush being connected with the power transmission shaft and the other end being connected with the positioning center.

3. The apparatus for removing the surface passivation layer of a lithium-containing strip as claimed in claim 2, wherein The end of the power transmission shaft in contact with the cylindrical brush is provided with a positioning center and a transmission pin for transmitting power.

4. The apparatus for removing a passivation layer from a surface of a lithium-containing strip as defined in claim 1, wherein, The cylindrical brush is composed of a shaft and bristles uniformly distributed on the shaft.

5. The apparatus for removing the surface passivation layer of a lithium-containing strip as claimed in claim 4, wherein The shaft of the cylindrical brush is provided with positioning holes or positioning surfaces at both ends.

6. The apparatus for removing a passivation layer from a surface of a lithium-containing strip as defined in claim 1, wherein, The fine adjustment assembly is composed of a gas cylinder and a fine adjustment mechanism, and can realize micron-level position adjustment.

7. The apparatus for removing a passivation layer from a surface of a lithium-containing strip as defined in claim 1, wherein, The fine adjustment assembly is arranged at both ends of the cylindrical brush, one end being arranged at the bearing seat of the power transmission shaft and the other end being arranged at the positioning center; the cylindrical brush can be made to approach or move away from the support backup roll.

8. The apparatus for removing a passivation layer from a surface of a lithium-containing strip as defined in claim 1, wherein, The fine adjustment assembly is arranged at the backup roll fixing seat at both ends of the support roller assembly, and the support backup roll can be made to approach or move away from the cylindrical brush.

9. The apparatus for removing a passivation layer from a surface of a lithium-containing strip as defined in claim 1, wherein, The device is further provided with a dust suction or collection device in the working area of the support backup roll and the cylindrical brush.

10. The apparatus for removing a passivation layer from a surface of a lithium-containing strip as defined in claim 1, wherein, The working environment of the device is an inert gas environment or a low dew point environment.

Images