Lithium battery separator cast sheet forming apparatus and method

Abstract

The lithium battery diaphragm casting sheet forming device disclosed by the application comprises a die head, a chilling roller, a first thickness gauge, a second thickness gauge and a die lip opening control device.The die head comprises a plurality of fine adjustment bolts for adjusting the die lip opening.The die lip opening control device comprises a controller and a screwing assembly.The controller is preset with a casting sheet target thickness.The controller is used for correcting the casting sheet target thickness according to the comparison result of the diaphragm actual thickness and the diaphragm target thickness, and controlling the screwing assembly to rotate the fine adjustment bolts according to the corrected casting sheet target thickness, so that the thickness of the casting sheet is stabilized in the range of the corrected casting sheet target thickness.The engineering and digital control method is used to replace the manual control of the die lip opening of the die head, the adjustment result of the die lip opening can be obtained in a short time, the phenomenon of low control precision, long time consumption and great waste of the die lip is eliminated, and stable production of high consistency diaphragm can be realized.

Description

Technical Field

[0001] This invention relates to the field of lithium battery separator preparation technology, specifically to a lithium battery separator casting apparatus and method. Background Technology

[0002] Lithium-ion battery separator thickness is a core parameter determining battery performance and safety, and its uniformity control is a key quality indicator in the production process. Uneven separator thickness distribution not only significantly degrades battery charge / discharge efficiency and cycle stability but may also lead to safety hazards such as localized thermal runaway or internal short circuits. Therefore, precise thickness testing must be performed before the separator winding process, and the die lip opening must be dynamically adjusted based on real-time testing data to ensure product homogeneity.

[0003] Current die lip opening adjustment technology mainly employs two implementation schemes: The traditional manual adjustment method uses a mechanical fine-tuning bolt structure. Operators analyze real-time data from a thickness gauge or record the thickness distribution by feel during winding, then use specialized tools to physically adjust the bolts at specific positions, thereby changing the die lip gap to preset parameters. While this method can control the diaphragm thickness, its effectiveness depends entirely on the operator's experience and skill level, resulting in significant variations in adjustment accuracy, fluctuating product yield, and poor quality consistency. The other adjustment method uses heat-sensitive materials to process fine-tuning bolts, controlling the die lip gap by adjusting the bolt length through electric heating. However, limited by the material's thermal expansion coefficient, its adjustment range is limited and difficult to adapt to production needs. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a lithium battery separator casting apparatus and method, which can achieve uniformity of separator thickness and obtain the adjustment results of the die lip opening in a short time. It has strong control stability, short adjustment cycle, and helps to reduce waste of raw materials.

[0005] To achieve the above objectives, the present invention provides a lithium battery separator casting apparatus, comprising:

[0006] The die head includes multiple fine-tuning bolts for adjusting the die lip opening;

[0007] Cooling rollers are used to cool sheets into cast sheets;

[0008] The first thickness gauge is used to measure the thickness of each transverse section of the casting.

[0009] The second thickness gauge is used to measure the thickness of each transverse section of the diaphragm;

[0010] The mold lip opening control device comprises a controller and a screwing assembly, the controller is preset with a target thickness of the cast sheet, the controller is used to correct the target thickness of the cast sheet according to the comparison result of the actual thickness of the diaphragm and the target thickness of the diaphragm, and control the screwing assembly to rotate the fine adjustment screw according to the corrected target thickness of the cast sheet, so that the thickness of the cast sheet is stabilized within the range of the corrected target thickness of the cast sheet.

[0011] In some embodiments, when the thickness data of a certain transverse interval of the diaphragm within a time period on the thickness data change curve exceeds a minimum threshold value and the slope of the curve within the time period exceeds a certain threshold value, the target thickness of the cast sheet is corrected based on the relationship between the actual thickness of the cast sheet and the actual thickness of the diaphragm within the time period.

[0012] In some embodiments, when the thickness data of a certain transverse interval of the diaphragm within a time period on the thickness data change curve exceeds a minimum threshold value and the slope of the curve within the time period exceeds a certain threshold value, the target thickness of the cast sheet is corrected based on the relationship between the actual thickness of the cast sheet and the actual thickness of the diaphragm within the time period.

[0013] In some embodiments, the thickness data of the cast sheet and the diaphragm is read from the first thickness gauge and the second thickness gauge every interval preset time;

[0014] The thickness data of the cast sheet and the diaphragm is compared with the preset target thickness data range, and a sound alarm and / or a prompt through a human-computer interaction interface is given when any of the thickness data exceeds the target thickness range.

[0015] In some embodiments, before formally starting the production process of the diaphragm, a reference sample of the diaphragm meeting the quality standard is obtained through trial production, and the target thickness range of the cast sheet is determined based on the thickness distribution data of the cast sheet recorded by the first thickness gauge.

[0016] In some embodiments, in the online production control stage, the thickness data change curves with production time as the horizontal axis are respectively drawn according to the thickness data collected by the first thickness gauge and the second thickness gauge; the target thickness range of the cast sheet is corrected according to the change trend of the thickness change curve corresponding to the second thickness gauge; and the opening of the mold lip is adjusted in real time according to the change trend of the thickness data change curve corresponding to the first thickness gauge.

[0017] In some embodiments, the driving mechanism comprises an X-axis moving module, a Y-axis moving module and a Z-axis moving module, the Z-axis moving module is arranged on the Y-axis moving module and is used to realize the movement in the Z-axis direction, the Y-axis moving module is arranged on the X-axis moving module and is used to realize the movement in the Y-axis direction, the X-axis moving module is used to realize the movement in the X-axis direction, and the screwing assembly is arranged on the Z-axis moving module.

[0018] In some embodiments, the X-axis moving module, the Y-axis moving module and the Z-axis moving module are realized by a ball screw nut pair.

[0019] In some embodiments, the screwing assembly comprises a sleeve for clamping the existing fine adjustment screw, and a motor for rotating the sleeve after the fine adjustment screw has been clamped by the sleeve.

[0020] In some embodiments, a position detection device is further included for detecting the position of the screwing assembly.

[0021] The present application also proposes a lithium battery separator sheet forming method, comprising the following steps:

[0022] The target thickness of the sheet and the separator is preset, and the sheet and the separator are divided into a plurality of lateral intervals along the lateral direction, and the lateral intervals have a corresponding relationship with the fine adjustment screw;

[0023] The thickness of each lateral interval of the sheet and the separator is measured by the first thickness gauge and the second thickness gauge respectively;

[0024] The time delay of obtaining the sheet thickness data and the separator thickness data is corrected according to the speed of mechanical flow;

[0025] The separator thickness is compared with the target thickness of the separator, and the target thickness of the sheet is corrected according to the comparison result;

[0026] The sheet thickness is compared with the target thickness of the sheet, and the opening of the die lip is adjusted according to the comparison result, so that the thickness of any lateral interval of the sheet is stabilized within the corresponding target range of the sheet.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] According to the data of the first thickness gauge and the second thickness gauge, the target thickness of the sheet can be corrected in real time, and the opening of the die lip is automatically controlled according to the target thickness of the sheet. Since the engineering and digital control method is used to replace the manual control of the opening of the die lip, the adjustment result of the opening of the die lip can be obtained in a short time, and the phenomenon of low control precision, long time consumption and large waste is eliminated, and the stable production of high consistency of the separator product can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0029] The above-mentioned characteristics, technical features, advantages and implementation modes of the present application will be further described in the following preferred embodiments in a clear and easy-to-understand manner, combined with the drawings.

[0030] Figure 1 is a structural schematic diagram of the lithium battery separator sheet forming device of the present application.

[0031] Figure 2 is a structure schematic view of the die lip opening control device of the lithium battery separator sheet forming device of the present application.

[0032] Figure 3 is Figure 2 is a structure schematic view of the mobile module.

[0033] BRIEF DESCRIPTION OF DRAWINGS

[0034] Die head 1; fine adjustment bolt 11; chilling roller 2; first thickness gauge 3; second thickness gauge 4; controller 5; driving mechanism 6; rack 61; X-axis mobile module 62; Y-axis mobile module 63; Z-axis mobile module 64; support seat 65; screwing assembly 7; sleeve 71; motor 72; stepper motor 81; screw nut seat 82; linear guide rail 83; guide rail slider 84. DETAILED DESCRIPTION

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, specific embodiments of the present application will be described below with reference to the drawings. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0036] Please refer to the description Figures 1 to 3 The lithium battery separator sheet forming system provided by an embodiment of the present application includes a die head 1, a chilling roller 2, a first thickness gauge 3, a second thickness gauge 4, and a die lip opening control device. The die head 1 is used to extrude the melt flowing out from the extruder into a sheet, and the die head 1 has a cavity, the bottom of which is provided with a fixed die lip and a movable die lip opposite to each other, and the fixed die lip and the movable die lip cooperate to form an extrusion gap, through which the high-temperature melt in the cavity of the die head 1 can flow out to form a sheet that flows from the side of the die head 1 to the side of the chilling roller 2. The chilling roller 2 is used to cool the sheet, so that the temperature of the high-temperature sheet is rapidly reduced below the glass transition temperature, and the sheet is converted from a viscous flow state to an amorphous solid sheet, avoiding crystallization affecting subsequent stretching, and after the sheet is stretched, extracted, dried, and other processes, a final separator product is formed.

[0037] In the embodiment, the movable die lip is provided with a plurality of fine adjustment bolts 11, which are distributed along the length direction of the movable die lip, for adjusting the gap of the extrusion slit. It should be noted that the transverse direction in the embodiment refers to the length direction of the extrusion slit. In the embodiment, the sheet, the cast sheet and the diaphragm can be divided into a plurality of transverse intervals in the transverse direction, and the transverse intervals have a corresponding relationship with the fine adjustment bolts 11. By rotating the fine adjustment bolts 11, the gap of the extrusion slit at the corresponding position can be increased or decreased, so as to adjust the thickness of the sheet, the cast sheet and the final diaphragm. The first thickness gauge 3 and the second thickness gauge 4 can move back and forth in the transverse direction. The first thickness gauge 3 is used to measure the thickness of each transverse interval of the cast sheet, and the second thickness gauge 4 is used to measure the thickness of each transverse interval of the diaphragm. The structure for driving the first thickness gauge 3 and the second thickness gauge 4 is not limited in the embodiment, for example, the first thickness gauge 3 and the second thickness gauge 4 are driven to move linearly by a linear guide rail or the like. The die lip opening control device in the embodiment controls the fine adjustment bolts 11 based on the data collected by the first thickness gauge 3 and the second thickness gauge 4, so as to adjust the thickness of the sheet in the transverse direction.

[0038] Before starting the diaphragm production process, a target thickness reference system needs to be established. A diaphragm reference sample meeting the quality standard is obtained through trial production, and the target thickness range of the cast sheet is determined based on the thickness distribution data of the cast sheet recorded by the first thickness gauge 3. In the embodiment, the system synchronously collects the thickness data of the first thickness gauge 3 (cast sheet detection) and the second thickness gauge 4 (diaphragm finished product detection) according to a preset sampling period, and establishes a thickness data change curve based thereon. The real-time data is compared with the target thickness. When the measured thickness of any detection point deviates from the target interval (the maximum threshold value is set to +8%, and the minimum threshold value is set to -5%), the system automatically activates the sound and light alarm and / or prompts through the human-computer interaction interface. The thickness data change curve is a curve with production time as the horizontal axis, which is drawn according to the thickness data collected by the first thickness gauge 3 and the second thickness gauge 4. The target thickness range includes the maximum threshold value and the minimum threshold value. For example, when any thickness data on the thickness data change curve of the diaphragm exceeds the maximum threshold value, a sound alarm and / or a prompt through the human-computer interaction interface can be given. For example, the thickness data change curve of the diaphragm is maintained near the minimum threshold value, indicating that the production process is normal. However, the present application is not limited thereto. In some embodiments of the present application, the condition for alarm / prompt can be set as that the thickness data of the diaphragm and the cast sheet exceeds the maximum threshold value or is less than the minimum threshold value at the same time.

[0039] In the online production control stage, the thickness data of each lateral section of the cast sheet is plotted as a function of production time based on the thickness data collected by the first thickness gauge 3, and the gap of the extrusion slit corresponding to each lateral section of the cast sheet is re-set based on the trend of the thickness data of each lateral section of the cast sheet. For example, when the thickness data of a certain lateral section of the cast sheet exceeds a minimum threshold value and the slope of the curve exceeds a certain threshold value within a certain time period, it indicates that the thickness data changes dramatically within the time period, and the opening of the die lip can be automatically adjusted to ensure that the thickness of any lateral section of the cast sheet is stable within the corresponding target range.

[0040] After the sheet is formed into a cast sheet, it still needs to go through the steps of stretching, extraction, drying, etc., and the factors affecting the final thickness of the separator membrane include the stretching ratio of each lateral section of the cast sheet, etc., so even if the thickness of the cast sheet is stable within the pre-set target range, when the temperature of a certain lateral section of the cast sheet changes or the stretching ratio changes, it will still affect the final thickness of the separator membrane. Therefore, in this embodiment, the system also plots the thickness data of each lateral section of the separator membrane as a function of production time based on the thickness data collected by the second thickness gauge 4, and re-sets the target thickness of the cast sheet based on the trend of the thickness data curve, and adjusts the gap of the extrusion slit corresponding to each lateral section of the cast sheet based on the re-set target thickness of the cast sheet. For example, when the thickness data of a certain lateral section of the separator membrane exceeds a minimum threshold value and the slope of the curve exceeds a certain threshold value within a certain time period, it indicates that the thickness data of the separator membrane changes dramatically within the time period, the stretching ratio of the cast sheet has changed, and the original set target thickness range of the cast sheet cannot meet the actual needs. The target thickness of the cast sheet can be corrected based on the relationship between the actual thickness of the cast sheet and the actual thickness of the separator membrane within the time period, and the opening of the die lip is adjusted based on the corrected target thickness of the cast sheet to ensure that the thickness of each lateral section of the cast sheet is stable within the corrected target range of the cast sheet.

[0041] It can be understood that the thickness of the diaphragm is determined by the thickness of the cast sheet and the subsequent stretching process. The greater the stretching ratio of the cast sheet, the smaller the thickness of the finished diaphragm. In the process of biaxial stretching, the cast sheet is stretched in the longitudinal direction (MD) and the transverse direction (TD), and the thickness is significantly reduced. The thickness conversion relationship between the cast sheet and the diaphragm is T_final = T_cast / (MD_ratio x TD_ratio), wherein T_final is the thickness of the diaphragm, T_cast is the thickness of the cast sheet, and MD_ratio and TD_ratio are the stretching ratios in the longitudinal direction and the transverse direction, respectively. For example, if the thickness of the cast sheet is 100 μm, the stretching ratio in the longitudinal direction is 3 times, and the stretching ratio in the transverse direction is 5 times, then the thickness of the finished diaphragm is about 100 / (3 x 5) = 6.67 μm. Therefore, based on the actual thickness of the diaphragm and the cast sheet, the stretching ratio of any transverse interval of the cast sheet can be determined, and the target thickness of the cast sheet can be corrected according to the stretching ratio, so as to ensure that the thickness of the finished diaphragm is always maintained within the predetermined range.

[0042] In this embodiment, a first thickness gauge 3 is arranged at the upstream end of the mechanical flow direction of the production line, and a second thickness gauge 4 is arranged at the downstream end. There is a predetermined distance between the two thickness gauges. Due to the time lag effect in the process of transporting the cast sheet, in order to match the data collected by the first thickness gauge 3 and the second thickness gauge 4, the thickness data collected by the first thickness gauge 3 and the second thickness gauge 4 need to be time-sequenced. As time-sequencing, the time delay (time lag) can be appropriately corrected according to the speed of the mechanical flow. Specifically, the distance between the first thickness gauge 3 and the second thickness gauge 4 is determined in advance, the time delay for obtaining the thickness data of the cast sheet and the thickness data of the diaphragm is corrected according to the speed of the mechanical flow, and the data is stored. In this way, the thickness data of the first thickness gauge 3 and the second thickness gauge 4 can correspond to each other respectively, and the time delay is corrected.

[0043] In this embodiment, the target thickness of the cast sheet can be corrected in real time according to the data of the first thickness gauge 3 and the second thickness gauge 4, and the opening of the die lip can be automatically controlled according to the target thickness of the cast sheet, so as to realize the uniformization of the diaphragm thickness. In addition, the adjustment of the opening of the die lip is based on the target thickness of the cast sheet. Since the distance between the die 1 and the first thickness gauge 3 is short, the adjustment result of the opening of the die lip can be obtained in a short time, which helps to reduce the waste of raw materials.

[0044] In this embodiment, the die lip opening control device comprises a controller 5, a driving mechanism 6 and a screwing assembly 7. The screwing assembly 7 is connected to the driving mechanism 6, and the controller 5 is signal connected to the driving mechanism 6 and the screwing assembly 7. The controller 5 is used to control the opening and closing of the driving mechanism 6 and the screwing assembly 7.

[0045] Specifically, please refer to the accompanying drawings Figure 1The screwing assembly 7 is connected to the driving mechanism 6, and the driving mechanism 6 is controlled by the controller 5 to drive the screwing assembly 7 to move to the fine adjustment screw 11, and the fine adjustment screw 11 is screwed by the screwing assembly 7, so that the die lip opening reaches the expected value.

[0046] The driving mechanism 6 comprises an X-axis moving module 62, a Y-axis moving module 63 and a Z-axis moving module 64. For the convenience of description, a right-hand XYZ orthogonal coordinate system is set with the direction of gravity as the reference, the length direction of the extrusion gap is set as the X-axis direction, the horizontal direction perpendicular to the X-axis direction is set as the Y-axis direction, and the direction perpendicular to the horizontal direction is set as the Z-axis direction.

[0047] The X-axis moving module 62 is used to realize the linear motion of the X-axis. The X-axis moving module 62 can be installed on the ground, for example, in the form of existing rails and rail wheels; the X-axis moving module 62 can also be suspended above the ground, for example, suspended on the ceiling in the room, using the existing row of hoist structure, therefore, the X-axis moving module 62 can be arranged according to the needs or the structure of the site, at the same time, the X-axis moving module 62 can use existing equipment, for example, a crane, a rail and rail wheel combination structure, a gear and rack, a gear and chain, a pulley system, a combination of a steel cable winch and a motor on both ends of a support base 65 to pull along the X-axis to realize the movement. The support base 65 is connected to the X-axis moving module 62, and the X-axis moving module 62 drives the movement of the support base 65 in the X-axis direction; the support base 65 can be used as a mounting base for parts, and the structure can be set as needed.

[0048] The Y-axis moving module 63 is used to realize the movement in the Y-axis direction. The Y-axis moving module 63 is movably connected to the support base 65, so as to be driven by the support base 65 to move in the X-axis direction, thereby realizing the position change of the Y-axis moving module 63 in the X-axis direction. The Y-axis moving module 63 can also use existing equipment such as ball screw nut pair, gear and rack, gear and chain, air cylinder, hydraulic cylinder and pulley system.

[0049] The Z-axis moving module 64 is used to realize the movement in the Z-axis direction. The Z-axis moving module 64 is connected to the Y-axis moving module 63, so as to be driven by the Y-axis moving module 63 to move, thereby realizing the position change of the Z-axis moving module 64 in the Y-axis direction.

[0050] As an example, the X-axis movement module 62 is connected to the rack 61, the Y-axis movement module 63 is arranged at the moving end of the X-axis movement module 62, the Z-axis movement module 64 is arranged at the moving end of the Y-axis movement module 63, and the screwing assembly 7 is arranged at the moving end of the Z-axis movement module 64, that is, the X-axis movement module 62, the Y-axis movement module 63 and the Z-axis movement module 64 are connected to the screwing assembly 7 in a series mode, so that the screwing assembly 7 can be used in cooperation with the X-axis movement module 62, the Y-axis movement module 63 and the Z-axis movement module 64 to realize movement in the X-axis, Y-axis and Z-axis directions.

[0051] In the embodiment, the X-axis movement module 62, the Y-axis movement module 63 and the Z-axis movement module 64 can adopt the same structural design and each include a stepping motor 81, a shaft coupling, a ball screw, a screw nut seat 82, a linear guide rail 83 and a guide rail slider 84. The output end of the stepping motor 81 is rigidly connected to the ball screw in a direct drive mode through the shaft coupling, the ball screw penetrates through the screw nut seat 82 and is threadedly connected to the screw nut seat 82, so that the screw nut seat 82 can precisely reciprocate along the axis of the ball screw when the stepping motor 81 is driven. The linear guide rail 83 extends along the axis of the ball screw, the guide rail slider 84 is fixedly installed on the screw nut seat 82, and the guide rail slider 84 and the linear guide rail 83 are in sliding fit, and the two constitute a double-direction limiting mechanism to ensure that the compound movement track of the screw nut seat 82 and the guide rail slider 84 is strictly controlled and the movement stroke is limited in the mechanical interval formed by the bearing seats on both sides of the ball screw. Thus, the movement modules in the embodiment are assembled in a hierarchical superposition mode, the Y-axis movement module 63 is integrally installed on the screw nut seat of the X-axis movement module 62, and the Z-axis movement module 64 is further mounted on the top of the screw nut seat of the Y-axis movement module 63, so as to realize precise displacement control in three-dimensional space through three-axis linkage.

[0052] The screwing assembly 7 is connected to the Z-axis movement module 64, so that the screwing assembly 7 is moved in the Z-axis direction by the Z-axis movement module 64 to realize the position change of the screwing assembly 7 in the Z-axis direction. Finally, the position of the screwing assembly 7 is adjusted through the position changes of the X-axis movement module 62, the Y-axis movement module and the Z-axis movement module 64, so as to realize the position adjustment. Since the position of the screwing assembly 7 is adjusted through automatic control, the position of the screwing assembly 7 can be precisely adjusted, and the accuracy of the alignment of the screwing assembly 7 with the fine adjustment bolt 11 when the fine adjustment bolt 11 is rotated by the screwing assembly 7 is realized.

[0053] The screwing assembly 7 comprises a sleeve 71 for clamping the fine adjustment screw 11, and a motor 72 for rotating the sleeve 71 after the fine adjustment screw 11 has been clamped by the sleeve 71. The sleeve 71 has a cavity matching the shape of the head of the fine adjustment screw 11, and the axial direction of the sleeve 71 is preferably parallel to the axial direction of the fine adjustment screw 11. In addition, the screwing assembly 7 further comprises a position detecting device for detecting the position of the screwing assembly 7, and the movement track of the screwing assembly 7 can be preset according to the installation position of different fine adjustment screws 11. In use, after the fine adjustment screw 11 to be adjusted is determined, the driving mechanism 6 is controlled by the controller 5 to drive the screwing assembly 7 to move, and the position detecting device checks whether the screwing assembly 7 has moved to the right position. After the screwing assembly 7 is aligned with the adjustment screw, a feedback signal is sent to the controller 5, and after the controller 5 determines that the screwing assembly 7 has moved to the right position, the screwing assembly 7 can perform the next action. In the embodiment, the position detecting device can be a position sensor, a visual detection device, etc., which is not limited herein.

[0054] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A method for forming lithium battery separator castings, characterized in that, A lithium battery separator casting equipment was adopted, which includes: The die head includes multiple fine-tuning bolts for adjusting the die lip opening; Cooling rollers are used to cool sheets into cast sheets; The first thickness gauge is used to measure the thickness of each transverse section of the casting. The second thickness gauge is used to measure the thickness of each transverse section of the diaphragm; The die lip opening control device includes a controller and a screwing component. The controller is preset with target thicknesses for the diaphragm and the casting sheet. The controller is used to correct the target thickness of the casting sheet based on the comparison between the actual thickness of the diaphragm and the target thickness, and to control the screwing component to rotate the fine-tuning bolt based on the corrected target thickness of the casting sheet, so that the thickness of the casting sheet is stabilized within the corrected target thickness range. The molding method includes the following steps: The target thickness of the casting and diaphragm is preset, and the casting and diaphragm are divided into several transverse intervals along the transverse direction. The transverse intervals correspond to the fine-tuning bolts. The thickness of each transverse section of the casting and diaphragm was measured using a first thickness gauge and a second thickness gauge, respectively. The time delay for obtaining casting thickness data and diaphragm thickness data is corrected based on the speed of mechanical flow. The diaphragm thickness is compared with the target diaphragm thickness, and the target thickness of the cast sheet is adjusted based on the comparison results; The thickness of the cast sheet is compared with the target thickness of the cast sheet, and the opening of the die lip is adjusted according to the comparison result so that the thickness of any transverse section of the cast sheet is stable within the corresponding target thickness range.

2. The lithium battery separator casting method according to claim 1, characterized in that: When the thickness data on the thickness data change curve of a certain transverse interval of the diaphragm exceeds the minimum threshold for a certain period of time and the slope of the curve exceeds a certain threshold during that period of time, the target thickness of the cast sheet is corrected based on the relationship between the actual thickness of the cast sheet and the actual thickness of the diaphragm during that period of time.

3. The lithium battery separator casting method according to claim 1, characterized in that: When the thickness data of a certain transverse section of the casting exceeds the minimum threshold for a certain period of time and the slope of the curve exceeds a certain threshold during that period of time, the controller controls the twisting component to rotate the fine-tuning bolt, so that the thickness of any transverse section of the casting is stabilized within the corresponding target range.

4. The lithium battery separator casting method according to claim 1, characterized in that, Also includes: At preset intervals, the thickness data of the casting and diaphragm are read from the first and second thickness gauges. The thickness data of the casting and diaphragm are compared with a preset target thickness data range. If any of the thickness data exceeds the target thickness range, an audible alarm is triggered and / or a prompt is given through a human-machine interface.

5. The lithium battery separator casting method as described in claim 1, characterized in that, Also includes: Before officially starting the diaphragm production process, a diaphragm reference sample that meets the quality standards is obtained through trial production. Based on the casting thickness distribution data recorded by the first thickness gauge, the target thickness range of the casting is determined.

6. The lithium battery separator casting method as described in claim 1, characterized in that, Also includes: During the online production control phase, thickness data change curves with production time as the horizontal axis are plotted based on the thickness data collected by the first and second thickness gauges. The target thickness range of the casting is corrected based on the trend of the thickness change curve corresponding to the second thickness gauge; the opening of the die lip is adjusted in real time based on the trend of the thickness data change curve corresponding to the first thickness gauge.

7. The lithium battery separator casting method according to claim 1, characterized in that, The tightening assembly includes a sleeve for engaging an existing fine-tuning bolt, and a motor for rotating the sleeve after the fine-tuning bolt has been engaged by the sleeve.

8. The lithium battery separator casting method according to claim 1, characterized in that, It also includes a position detection device for detecting the position of the twisting component.

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