Vacuum liquid suction device for lithium battery diaphragm extracting and drying process and extracting and drying device

Abstract

The invention discloses a vacuum liquid suction device and an extraction drying device.The vacuum liquid suction device comprises a liquid suction roller, and the liquid suction roller comprises a hollow outer roller and an inner roller which are coaxially arranged; the inner roller is located in an inner cavity of the hollow outer roller, an annular liquid suction cavity is formed between the outer wall of the inner roller and the inner wall of the hollow outer roller, liquid suction holes communicated with the liquid suction cavity are evenly distributed in the hollow outer roller, and the liquid suction cavity in a negative pressure state can form a negative pressure adsorption microenvironment at inlets of the liquid suction holes; and the liquid suction roller in contact with the diaphragm can adsorb the extraction liquid on the surface of the diaphragm under negative pressure. The extraction drying device comprises a vacuum liquid suction device arranged between the liquid level of the extraction liquid and drying rollers, and the liquid suction rollers arranged in pairs make contact with the front face and the back face of the diaphragm correspondingly so as to adsorb the extraction liquid on the front face and the back face of the diaphragm through negative pressure. Through the innovative micropore design and the negative pressure adsorption technology, the consistency of the diaphragm surface defect and the diaphragm is remarkably improved, and the product yield is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium battery diaphragm production, and in particular relates to an extraction and drying process, specifically a vacuum liquid suction device and an extraction and drying device used in the extraction and drying process of lithium battery diaphragm. Background Art

[0002] In the production process of lithium battery separators, the separator needs to go through a series of process steps such as feeding extrusion, casting, stretching, drying, and extraction. The extraction and drying process is crucial to the performance and quality of the separator. In the extraction and drying process, the solvent on the surface of the separator needs to be effectively removed. The traditional extraction and drying method uses a static stainless steel roller with a smooth surface for scraping liquid. There are problems such as uneven solvent removal and low efficiency, and it is difficult to ensure the consistency of the separator. In addition, if the impurities generated during the scraping process are not handled in time, the residual water stains on the surface will form scale after heating, and other residual solvents will adhere to the scale surface, resulting in heterogeneous crystals on the roller surface, resulting in an increase in film surface defects. This drying device requires operators to enter the drying furnace to clean the roller surface once a day. The drying furnace is a closed space and contains dichloromethane (MC) gas. Each cleaning requires stopping production. Daily cleaning seriously affects production efficiency, and entering the drying furnace for cleaning has great safety hazards, making it difficult to meet the production needs of high-quality lithium battery separators. Therefore, a new type of solvent removal device is needed to solve these problems. Summary of the invention

[0003] The purpose of the present invention is to address the problems existing in the prior art and to provide a vacuum liquid suction device and an extraction and drying device for the extraction and drying process of lithium battery diaphragms; the extraction and drying device with a vacuum liquid suction device can reduce the elution residual solvent attached to the surface of the diaphragm, improve the liquid suction efficiency, and ensure the uniformity of liquid suction, thereby reducing the defects of lithium battery diaphragms and improving the consistency of the diaphragms, and solving the technical problem of large safety hazards in cleaning.

[0004] The purpose of the present invention is to be solved by the following technical solutions: A vacuum liquid suction device for the extraction and drying process of lithium battery diaphragms, characterized in that: the vacuum liquid suction device includes a liquid suction roller, the liquid suction roller includes a coaxially arranged hollow outer roller and an inner roller, the inner roller is located in the inner cavity of the hollow outer roller and an annular liquid suction cavity is formed between the outer wall of the inner roller and the inner wall of the hollow outer roller, liquid suction holes connected to the liquid suction cavity are evenly distributed on the hollow outer roller, and the liquid suction cavity maintained in a negative pressure state can form a negative pressure adsorption microenvironment at the inlet of the liquid suction hole; the liquid suction roller in contact with the diaphragm can negatively pressure adsorb the extraction liquid on the surface of the diaphragm.

[0005] The diameter of the liquid suction roller is 120 mm to 180 mm, which is 1.5 to 2.0 times the diameter of a traditional roller.

[0006] The wall thickness of the hollow outer roller is 6 mm to 9 mm, and the depth of the liquid suction cavity is 7 mm to 8 mm.

[0007] The inner roller can be hollow or solid as required. If the overall weight of the suction roller is to be reduced to make it lighter, the inner roller can be hollow.

[0008] The negative pressure in the liquid suction cavity is not less than -0.5MPa; the aperture of the liquid suction hole is 2.5±0.5mm, the hole depth is 7.5±1.5mm, the axial spacing of the liquid suction holes is 50mm~150mm, and the circumferential spacing is 25mm~40mm; and the inlet of the liquid suction hole is arranged with a chamfer with a curvature of 0.5±0.1mm.

[0009] One end of the inner roller is connected to the corresponding end of the inner cavity of the hollow outer roller by an inter-roller connecting portion. The inter-roller connecting portion provided with a liquid guide port and the end wall of the inner roller and the inner cavity end wall of the hollow outer roller form a transition chamber connected to the liquid absorption chamber. The transition chamber capable of transferring and temporarily storing the extraction liquid is connected to the central axis hole of the hollow outer roller through the liquid guide port.

[0010] A plurality of elliptical liquid guide ports are evenly distributed on the inter-roller connecting portion, and the short axes of the liquid guide ports are arranged along the axial direction of the liquid suction roller.

[0011] The protruding part of the rotary joint is embedded in the central axis hole of the suction roller, and the through inner cavity of the rotary joint and the central axis hole of the suction roller constitute a liquid guide cavity for outputting the extraction liquid adsorbed by the negative pressure of the suction roller; at least one annular sealing groove is arranged on the outer wall of the distal end of the protruding part of the rotary joint, and a sealing ring is embedded in the sealing groove.

[0012] The vacuum liquid suction device also includes a liquid storage chamber, which is arranged on the driving side of the liquid suction roller and is connected to the liquid suction chamber through a liquid guide chamber at one end of the liquid storage chamber, and the other end of the liquid guide chamber is connected to the waste liquid tank through a liquid discharge elbow; a filter screen sleeve is arranged on the liquid discharge elbow, and the filter screen sleeve is composed of a combination of a 40-mesh filter screen and a 60-mesh filter screen; a pipeline is arranged on the liquid discharge elbow or on the waste liquid tank to connect to a negative pressure fan.

[0013] The liquid storage chamber includes a liquid storage chamber shell and a liquid guide ring. The liquid storage chamber shell is welded and fixed to the outer shell of the driving motor. The liquid guide ring is clamped inside the liquid storage chamber shell with a gasket and abuts against the outlet end of the liquid guide chamber, playing a guiding and sealing role to prevent the extraction liquid from entering the gap between the rotary joint and the coupling.

[0014] The suction roller is installed in the bearing of the roller mounting seat, and the driving end of the suction roller is connected to the power output end of the driving motor through a hollow rotating joint and a coupling in sequence. The driving motor is fixedly installed on the outside of the roller mounting seat; the driving motor drives the suction roller to rotate through the coupling and the rotating joint.

[0015] The roller mounting seat for mounting the liquid suction roller is arranged on a sliding bracket with a slide rail. The bottom of the roller mounting seat is embedded in the slide rail and can move linearly on the slide rail under the drive of the corresponding track motor. The track motor is controlled and operated by a controller, and the controller is arranged on the roller mounting seat on the non-driving end side of the liquid suction roller; the controller can adjust the linear movement of the roller mounting seat by 100mm to 150mm through the track motor, thereby adjusting the wrap angle range between the liquid suction roller and the diaphragm between 40° and 180°.

[0016] A pressure sensor is arranged on the liquid suction roller and the real-time pressure monitored by the pressure sensor can be output to the controller, and the controller adjusts the negative pressure state of the liquid suction chamber through the negative pressure fan.

[0017] An extraction and drying device adopts the above-mentioned vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm. The vacuum liquid suction device arranged in the extraction and drying box is located between the liquid surface of the extraction liquid and the drying roller. The paired liquid suction rollers are arranged parallel to the extraction rollers in the extraction liquid and the drying rollers above the extraction liquid. The paired liquid suction rollers are respectively in contact with the front and back sides of the diaphragm to absorb the extraction liquid on the front and back sides of the diaphragm with negative pressure.

[0018] Compared with the prior art, the present invention has the following advantages: The vacuum liquid suction device of the present invention can ensure that the solvent on the diaphragm is evenly absorbed by arranging evenly distributed liquid suction holes on the surface of the roller body, thereby improving the quality of the diaphragm; by accurately controlling the micropore diameter, arrangement method and negative pressure range of the roller body surface, combined with an increased liquid suction roller diameter and negative pressure adsorption technology, a more efficient and uniform extraction effect is achieved, and the consistency and product quality of the diaphragm are significantly improved; compared with a traditional scraping roller with a smooth and pore-free surface of the same diameter, the liquid suction roller can reduce the occurrence rate of appearance defects on the extraction membrane surface by more than 97%.

[0019] The negative pressure adsorption of the vacuum liquid suction device of the present invention can effectively drive the solvent into the liquid suction cavity through the liquid suction hole and be effectively sucked away, further improving the liquid removal efficiency and extractant recovery efficiency on the diaphragm surface, reducing the waste and escape of the extractant; and can increase the extractant recovery rate by about 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 A schematic diagram of the structure of a vacuum liquid suction device for the extraction and drying process of a lithium battery diaphragm provided by the present invention; Attached Figure 2 A schematic cross-sectional structural diagram of a liquid suction roller and a driving side of a vacuum liquid suction device for a lithium battery separator extraction and drying process provided by the present invention; Attached Figure 3An enlarged view of the liquid suction hole of the vacuum liquid suction device used in the lithium battery diaphragm extraction and drying process provided by the present invention; Attached Figure 4 This is a schematic structural diagram of the vacuum liquid suction device provided by the present invention when used in an extraction and drying device.

[0021] Among them: 1—liquid suction roller; 11—hollow outer roller; 12—inner roller; 13—liquid suction hole; 14—liquid suction chamber; 15—transition chamber; 16—roller connection; 17—liquid guide port; 18—central axis hole; 2—rotating joint; 21—sealing groove; 22—sealing ring; 3—liquid guide chamber; 4—coupling; 5—driving motor; 6—liquid storage chamber; 7—liquid discharge elbow; 8—roller mounting seat; 9—sliding bracket; 10—controller; 200—extraction roller; 300—drying roller. DETAILED DESCRIPTION

[0022] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0023] The terms "a", "an", "the", and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0024] like Figure 1-3 As shown: A vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm, the vacuum liquid suction device comprises a liquid suction roller 1, the liquid suction roller 1 comprises a coaxially arranged hollow outer roller 11 and an inner roller 12, the inner roller 12 is located in the inner cavity of the hollow outer roller 11, and an annular liquid suction cavity 14 is formed between the outer wall of the inner roller 12 and the inner wall of the hollow outer roller 11, and liquid suction holes 13 connected to the liquid suction cavity 14 are evenly distributed on the hollow outer roller 11, and the negative pressure in the liquid suction cavity 14 is not less than -0.5 MPa, the aperture of the liquid suction hole 13 is 2.5±0.5mm, and the hole depth is 7.5±1.5mm; the axial spacing of the liquid suction holes 13 is 50mm~150mm, the circumferential spacing is 25mm~40mm, and the inlet of the liquid suction hole 13 is arranged with a chamfer with an arc of 0.5±0.1mm; the liquid suction cavity 14 maintained in a negative pressure state can form a negative pressure adsorption microenvironment at the inlet of the liquid suction hole 13, and the liquid suction roller 1 in contact with the diaphragm can negatively pressure adsorb the extraction liquid on the surface of the diaphragm.

[0025] In the above structure, one end of the inner roller 12 is connected to the corresponding end of the inner cavity of the hollow outer roller 11 by an inter-roller connecting portion 16. The inter-roller connecting portion 16 provided with a liquid guide port 17 and the end wall of the inner roller 12 and the inner cavity end wall of the hollow outer roller 11 form a transition chamber 15 connected to the liquid suction chamber 14. The transition chamber 15 capable of transferring and temporarily storing the extraction liquid is connected to the central axis hole 18 of the hollow outer roller 11 through the liquid guide port 17. The short axes of several elliptical liquid guide ports 17 are arranged along the axial direction of the liquid suction roller 1.

[0026] like Figure 1-2 As shown, when the suction roller 1 is installed, the suction roller 1 is installed in the bearing of the roller mounting seat 8 and the driving end of the suction roller 1 is connected to the power output end of the driving motor 5 through the hollow rotary joint 2 and the coupling 4 in turn, and the driving motor 5 is fixedly installed on the outside of the roller mounting seat 8; the roller mounting seat 8 on which the suction roller 1 is installed is arranged on a sliding bracket 9 with a slide rail, and the bottom of the roller mounting seat 8 is embedded in the slide rail and can move linearly on the slide rail under the drive of the corresponding track motor, and the track motor is controlled by the controller 10, and the controller 10 is arranged on the roller mounting seat 8 on the non-driving end side of the suction roller 1; the controller 10 can adjust the roller mounting seat 8 to move linearly by 100mm to 150mm through the track motor, so as to adjust the wrap angle range between the suction roller 1 and the diaphragm between 40° and 180°. In addition, a pressure sensor is arranged on the suction roller 1 and the real-time pressure monitored by the pressure sensor can be output to the controller 10, and the controller 10 adjusts the negative pressure state of the suction chamber 14 through the negative pressure fan.

[0027] Specifically, the central axis hole 18 of the liquid suction roller 1 is embedded in the extension of the rotary joint 2, and the through inner cavity of the rotary joint 2 and the central axis hole 18 of the liquid suction roller 1 form a liquid guide cavity 3 for outputting the extraction liquid adsorbed by the liquid suction roller 1 under negative pressure; in order to maintain the sealing performance of the liquid guide cavity 3, at least one annular sealing groove 21 is arranged on the outer wall of the distal end of the extension of the rotary joint 2, and a sealing ring 22 is embedded in the sealing groove 21. The driving motor 5 drives the liquid suction roller 1 to rotate through the coupling 4 and the rotary joint 2.

[0028] Furthermore, the vacuum liquid suction device also includes a liquid storage chamber 6, which is arranged on the driving side of the liquid suction roller 1 and is connected to the liquid suction chamber 14 through the liquid guide chamber 3 at one end of the liquid storage chamber 6, and the other end of the liquid guide chamber 3 is connected to the waste liquid tank through the drainage elbow 7; the drainage elbow 7 is provided with a filter sleeve, and the filter sleeve is composed of a 40-mesh filter and a 60-mesh filter combination; preferably, a pipeline is arranged on the drainage elbow 7 or the waste liquid tank to connect to the negative pressure fan.

[0029] like Figure 4As shown, an extraction and drying device adopts the above-mentioned vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm. The vacuum liquid suction device arranged in the extraction and drying box is located between the liquid surface of the extraction liquid and the drying roller 300. The paired liquid suction rollers 1 are arranged parallel to the extraction rollers 200 in the extraction liquid and the drying rollers 300 above the extraction liquid. The paired liquid suction rollers 1 are in contact with the front and back sides of the diaphragm respectively to absorb the extraction liquid on the front and back sides of the diaphragm with negative pressure. The specific installation method is: two platforms are respectively located on both sides of the front and back sides of the diaphragm in the box, and each platform is connected to the sliding bracket 9 in the vacuum liquid suction roller device. Example

[0030] like Figure 1-3 As shown: a vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm, the vacuum liquid suction device includes a liquid suction roller 1, a rotary joint 2, a liquid guide cavity 3, a coupling 4, a drive motor 5, a liquid storage cavity 6, a liquid discharge elbow 7, a roller mounting seat 8, a sliding bracket 9, and a controller 10. The liquid suction roller 1 is installed in the bearing of the roller mounting seat 8 and the driving end of the liquid suction roller 1 is connected to the power output end of the drive motor 5 through the hollow rotary joint 2 and the coupling 4 in turn, and the drive motor 5 is fixedly installed on the outside of the roller mounting seat 8; the roller mounting seat 8 on which the liquid suction roller 1 is installed is arranged on a sliding bracket 9 with a slide rail, the bottom of the roller mounting seat 8 is embedded in the slide rail and can move linearly on the slide rail under the drive of the corresponding track motor, and the track motor is controlled and operated by the controller 10, and the controller 10 is arranged on the non-driving end side of the liquid suction roller 1. On the roller mounting seat 8; the extension of the rotary joint 2 is embedded in the central axis hole 18 of the liquid suction roller 1, and the through inner cavity of the rotary joint 2 and the central axis hole 18 of the liquid suction roller 1 constitute a liquid guide cavity 3 for outputting the extraction liquid adsorbed by the negative pressure of the liquid suction roller 1; in order to maintain the sealing performance of the liquid guide cavity 3, at least one annular sealing groove 21 is arranged on the outer wall of the distal end of the extension of the rotary joint 2, and a sealing ring 22 is embedded in the sealing groove 21 to achieve static sealing. At the same time, due to the large pressing force of the static seal (a suitable sealing ring with self-tightening sealing effect is selected, and the radial and axial forces depend on the pressure of the system. As the pressure rises, the compression deformation of the sealing ring will increase, and the total sealing force will increase, which can generate a large friction force), the output of the drive motor 5 can be transmitted to the liquid suction roller 1 through friction, so as to realize the active rotation of the liquid suction roller 1. The drive motor 5 in this scheme uses a small servo motor, which is driven by a magnetic connection for more precise control.

[0031] Specifically, the liquid suction roller 1 comprises a hollow outer roller 11 and an inner roller 12 which are coaxially arranged. The hollow outer roller 11 and the inner roller 12 are made of corrosion-resistant stainless steel to improve their wear resistance and corrosion resistance. The surface of the hollow outer roller 11 is densely covered with microporous liquid absorption holes 13, the aperture of the liquid absorption holes 13 is 2.5±0.5 mm, and the inlet shape of the liquid absorption holes 13 is carefully designed, all of which are fine rounded structures to ensure that the solvent can be effectively absorbed and the membrane can be prevented from being sucked into the liquid absorption holes 13 to cause membrane surface defects such as imprints or scratches; the arrangement of the liquid absorption holes 13 adopts a uniform distribution to maximize the contact area with the membrane and improve the extraction efficiency; the inner roller 12 is a closed cylinder with a smooth surface and no holes. The main function is to form a narrow cavity between the inner wall of the hollow outer roller 11, that is, the liquid absorption cavity 14, so that the negative pressure system can be vacuumed into a negative pressure, so that the oil film forms a negative pressure adsorption on the roller surface of the liquid absorption roller 1; secondly, the absorbed extraction liquid is collected from the surface of the inner roller 12 and reaches the transition cavity 15 along the direction of the negative pressure, and is discharged from the elliptical liquid guide port 1 (3-4 are set on the circumferential side) into the liquid guide cavity 3 on the driving side (the side with the driving motor 5).

[0032] The adsorption fan, the liquid absorption chamber 14, and the liquid absorption holes 13 form an efficient vacuum chamber and a micropore distribution network to ensure a uniform liquid absorption effect. The adsorption fan is connected to the inside of the roller body of the liquid absorption roller 1. By adjusting the frequency of the adsorption fan, the negative pressure inside the liquid absorption chamber 14 reaches 0.3-1 MPa, and the negative pressure state in the liquid absorption chamber 14 is maintained to drive the solvent into the liquid absorption chamber 14 through the liquid absorption holes 13; the negative pressure range is set within a reasonable range, which can not only ensure the effective removal of the solvent, but also avoid damage to the equipment and loss of the membrane surface caused by excessive negative pressure.

[0033] The liquid storage chamber 6 is arranged at one end of the driving side of the suction roller 1, that is, it is arranged at the tail end of the liquid guide chamber 3 and is connected to the liquid guide chamber 3. The liquid discharge elbow 7 is formed by connecting two straight pipes and a 90° elbow. The short straight pipe connects the liquid storage chamber 6 and the 90° elbow, and a filter sleeve is installed at the connection between the short straight pipe and the 90° elbow. The 90° elbow is connected to the long straight pipe, and a filter sleeve is installed at the connection between the 90° elbow and the long straight pipe. The filter sleeves use a 40-mesh + 60-mesh double-layer filter. Finally, the other end of the long straight pipe is connected to the waste liquid tank; the waste liquid tank is used to receive and temporarily store the solvent and impurities discharged from the inside of the roller body, and filter them to prevent the impurities from being deposited inside the equipment.

[0034] The controller 10 is used to control the negative pressure strength in the suction roller 1 to ensure that it operates within the set pressure range; the controller 10 is used to control the distance that the suction roller 1 moves toward each other on the upper and lower sliding brackets 9, thereby adjusting the size of the wrap angle and the contact area between the roller surface of the suction roller 1 and the membrane. The wrap angle is adjusted between 40° and 180°. In actual use, the wrap angles of both suction rollers 1 will not be 180°, but there is a state where the wrap angle of one suction roller 1 is directly up and down 180°. When the membrane surface is severely scratched, the wrap angle of one suction roller 1 will be adjusted to 180, which is basically close to the diaphragm and is not subjected to force; the controller 10 is also used to control the operation of the drive motor 5, the power of the adsorption fan, etc.

[0035] In order to cope with the extraction effect of high-viscosity solvents, the roller body design of the suction roller 1 in this embodiment adopts special materials, such as stainless steel or ceramics, to improve its wear resistance and corrosion resistance. The roller body diameter of the suction roller 1 is set to 1.5 times that of the traditional roller body. The thickening of the roller body diameter of the suction roller 1 can increase the adsorption area to enhance the fluidity and adsorption effect of the solvent on the roller surface. The negative pressure is not less than -0.5MPa to ensure effective extraction under high-viscosity solvents. The experimental results show that this embodiment shows significant superiority in extracting high-viscosity solvents, and the scraping efficiency is improved by more than 40% compared with the traditional method; and the suction roller 1 can reduce the appearance defect rate of the extraction membrane surface by more than 97%. Example

[0036] This embodiment is optimized for a large-scale production environment, and the suction roller 1 can be designed into a modular structure. The roller body of the suction roller 1 is composed of a plurality of detachable modules, each of which is densely covered with micropores as suction holes 13, and the micropore diameter and arrangement can be customized according to production requirements. This design is easy to maintain and replace, reducing production costs. At the same time, in order to meet the high flow requirements in large-scale production, a multi-stage pump design is used as a vacuum system to provide a negative pressure environment, which can provide a stronger negative pressure suction.

[0037] In practical applications, this embodiment exhibits excellent stability and high efficiency, meeting the stringent requirements of large-scale production on extraction efficiency and consistency.

[0038] The present invention uses innovative micropore design and negative pressure adsorption technology to optimize the micropore diameter and arrangement of the roller surface and set a reasonable negative pressure range. Combined with increasing the angle between the roller and the membrane, it significantly improves the membrane surface defects and the consistency of the diaphragm, thereby improving the product yield.

[0039] In the embodiments of the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installation", "connection", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0040] In the description of the embodiments of the present invention, it needs to be understood that the directions or positional relationships indicated by the terms "upper" and "lower" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the embodiments of the present invention.

[0041] In the description of this specification, the description of the terms "one embodiment", "a preferred embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0042] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention; any technology not involved in the present invention can be realized by existing technologies.

Claims

1. A vacuum liquid suction device for the extraction and drying process of lithium battery diaphragms, characterized in that: The vacuum liquid suction device comprises a liquid suction roller (1), the liquid suction roller (1) comprising a hollow outer roller (11) and an inner roller (12) which are coaxially arranged, the inner roller (12) being located in the inner cavity of the hollow outer roller (11), and an annular liquid suction cavity (14) being formed between the outer wall of the inner roller (12) and the inner wall of the hollow outer roller (11), and liquid suction holes (13) which are connected to the liquid suction cavity (14) being evenly distributed on the hollow outer roller (11), the liquid suction cavity (14) which maintains a negative pressure state can form a negative pressure adsorption microenvironment at the inlet of the liquid suction hole (13); the liquid suction roller (1) which is in contact with the diaphragm can negatively pressure adsorb the extraction liquid on the surface of the diaphragm.

2. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 1, characterized in that: The negative pressure in the liquid suction cavity (14) is not less than -0.5 MPa; the diameter of the liquid suction hole (13) is 2.5±0.5 mm, the hole depth is 7.5±1.5 mm, the axial spacing of the liquid suction holes (13) is 50 mm to 150 mm, and the circumferential spacing is 25 mm to 40 mm; and the inlet of the liquid suction hole (13) is arranged with a chamfer with a curvature of 0.5±0.1 mm.

3. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 1 is characterized in that: One end of the inner roller (12) is connected to the corresponding end of the inner cavity of the hollow outer roller (11) by an inter-roller connecting portion (16); the inter-roller connecting portion (16) provided with a liquid guide port (17) and the end wall of the inner roller (12) and the inner cavity end wall of the hollow outer roller (11) form a transition chamber (15) connected to the liquid suction chamber (14); the transition chamber (15) capable of transferring and temporarily storing the extraction liquid is connected to the central axis hole (18) of the hollow outer roller (11) through the liquid guide port (17).

4. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 3 is characterized in that: A plurality of elliptical liquid guide ports (17) are evenly distributed on the inter-roller connecting portion (16), and the short axes of the liquid guide ports (17) are arranged along the axial direction of the liquid suction roller (1).

5. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 1, characterized in that: The central axis hole (18) of the liquid suction roller (1) is embedded with the extension of the rotary joint (2), and the through inner cavity of the rotary joint (2) and the central axis hole (18) of the liquid suction roller (1) form a liquid guide cavity (3) for outputting the extraction liquid adsorbed by the liquid suction roller (1) under negative pressure; at least one annular sealing groove (21) is arranged on the outer wall of the distal end of the extension of the rotary joint (2), and a sealing ring (22) is embedded in the sealing groove (21).

6. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 5, characterized in that: The vacuum liquid suction device further comprises a liquid storage chamber (6), the liquid storage chamber (6) being arranged on the driving side of the liquid suction roller (1) and being connected to the liquid suction chamber (14) through the liquid guide chamber (3) at one end of the liquid storage chamber (6), and the other end of the liquid guide chamber (3) being connected to the waste liquid tank through a liquid discharge elbow (7); a filter screen sleeve is arranged on the liquid discharge elbow (7), and the filter screen sleeve is composed of a combination of a 40-mesh filter screen and a 60-mesh filter screen; a pipeline is arranged on the liquid discharge elbow (7) or the waste liquid tank to connect to the negative pressure fan.

7. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 1, characterized in that: The liquid suction roller (1) is mounted in the bearing of the roller mounting seat (8), and the driving end of the liquid suction roller (1) is connected to the power output end of the driving motor (5) through the hollow rotating joint (2) and the coupling (4) in sequence, and the driving motor (5) is fixedly mounted on the outside of the roller mounting seat (8); the driving motor (5) drives the liquid suction roller (1) to rotate through the coupling (4) and the rotating joint (2).

8. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 1, characterized in that: The roller mounting seat (8) for mounting the liquid suction roller (1) is arranged on a sliding bracket (9) with a slide rail. The bottom of the roller mounting seat (8) is embedded in the slide rail and can move linearly on the slide rail under the drive of a corresponding track motor. The track motor is controlled and operated by a controller (10). The controller (10) is arranged on the roller mounting seat (8) on the non-driving end side of the liquid suction roller (1). The controller (10) can adjust the linear movement of the roller mounting seat (8) by 100 mm to 150 mm through the track motor, thereby adjusting the wrap angle range between the liquid suction roller (1) and the diaphragm between 40° and 180°.

9. The vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm according to claim 1, characterized in that: The suction roller (1) is provided with a pressure sensor, and the real-time pressure monitored by the pressure sensor can be output to the controller (10). The controller (10) adjusts the negative pressure state of the suction chamber (14) through a negative pressure fan.

10. An extraction and drying device, the extraction and drying device adopts the vacuum liquid suction device for the extraction and drying process of lithium battery diaphragm as described in any one of claims 1 to 9, the vacuum liquid suction device arranged in the extraction and drying box is located between the liquid surface of the extraction liquid and the drying roller (300), the paired liquid suction rollers (1) are arranged parallel to the extraction roller (200) in the extraction liquid and the drying roller (300) above the extraction liquid, the paired liquid suction rollers (1) are respectively in contact with the front and back surfaces of the diaphragm, and the extraction liquid on the front and back surfaces of the diaphragm is adsorbed by negative pressure.

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