Battery pole piece coating control method and system and coating equipment

Abstract

The invention relates to a battery pole piece coating control method and system and coating equipment. The method comprises the following steps: S1, after a coating die head starts coating, acquiring a current coating pressure value of the coating die head; s2, according to the current coating pressure value, the set coating pressure value and the size relation between the current coating pressure value and the set coating pressure value, based on a preset algorithm, a target execution value of the adjusting part is calculated; s3, according to the target execution value of the adjusting part, the adjusting part is controlled to execute corresponding adjustment so as to adjust the backflow amount of the slurry distributed into the backflow pipeline by the flow distribution chamber, and the next coating pressure value of the coating die head can be close to the set coating pressure value; and S4, the next coating pressure value of the coating die head is obtained and serves as the current coating pressure value, and the steps S2 to S3 are repeated till coating of the battery pole piece is completed. According to the scheme provided by the invention, constant-pressure slurry supply can be realized through closed-loop control, digitization and intelligentization of a pole piece production process are realized, and the production efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of pole piece production, and particularly to a battery pole piece coating control method and system. Background Art

[0002] Pole piece coating generally refers to a process of uniformly coating a well-stirred slurry on a current collector and drying the organic solvent in the slurry. The coating effect has an important impact on battery capacity, internal resistance, cycle life, and safety. During the coating production process, a constant-pressure and stable slurry feeding system plays an important role in high-quality coating products. However, during the coating production process, fluctuations in the pump speed of the screw pump motor, unstable real-time liquid level height in the slurry buffer tank, etc., which lead to unstable hydraulic pressure, abnormal fluctuations in the air pressure of the air pipe, and blockage of filter elements by particles, etc., will all cause unstable coating pressure.

[0003] In the related art, generally, an operator will manually adjust the opening degree of the reflux valve and finely adjust the pump speed of the feeding pump according to experience to keep the coating pressure stable within the set pressure range.

[0004] However, this adjustment method completely relies on manual experience, and it is difficult to guarantee the debugging effect. Moreover, each time the product type is changed, manual re-debugging is required, which is extremely unfavorable to the production efficiency of pole piece coating. Summary of the Invention

[0005] To solve or partially solve the problems existing in the related art, the present application provides a battery pole piece coating control method, system, and coating equipment, which can automatically achieve constant-pressure feeding of the slurry through closed-loop control, keep the coating pressure stable, and improve production efficiency.

[0006] The first aspect of the present application provides a battery pole piece coating control method, including: S1. After the coating die starts coating, obtain the current coating pressure value of the coating die; S2. Based on a preset algorithm, calculate the target execution value of the adjusting member according to the current coating pressure value, the set coating pressure value, and their magnitude relationship; S3. According to the target execution value of the adjusting member, control the adjusting member to perform corresponding adjustments to adjust the slurry return flow rate distributed from the flow distribution chamber into the return pipeline, so that the next coating pressure value of the coating die is close to the set coating pressure value; S4. Obtain the next coating pressure value of the coating die and use it as the current coating pressure value, and repeat steps S2 to S3 until the coating of the battery pole piece is completed. As an optional embodiment, step S2 includes: Obtain the upper coating pressure value and the previous coating pressure value of the coating die head, and calculate the difference between the upper coating pressure value and the previous coating pressure value of the coating die head, and use it as the first difference; Calculate the difference between the previous coating pressure value and the current coating pressure value of the coating die head, and use it as the second difference; Based on the first difference, the second difference, the current coating pressure value and the set coating pressure value, calculate the current adjustment value of the adjusting part based on the first preset algorithm; Based on the current adjustment value and the previous adjustment value of the adjusting part, and the magnitude relationship between the current coating pressure value and the set coating pressure value, calculate the target execution value of the adjusting part based on the second preset algorithm.

[0007] As an optional embodiment, the first preset algorithm is a PID control algorithm. The step of calculating the current adjustment value of the adjusting part based on the first difference, the second difference, the current coating pressure value and the set coating pressure value includes: Set the proportional coefficient, integral coefficient and differential coefficient; Use the product of the second difference and the proportional coefficient as the proportional result; Use the product of the difference between the current coating pressure value and the set coating pressure value and the integral coefficient as the integral result; Use the product of the difference between the second difference and the first difference and the differential coefficient as the differential result; Accumulate the proportional result, the integral result and the differential result, and use it as the current adjustment value of the adjusting part.

[0008] As an optional embodiment, the step of calculating the target execution value of the adjusting part based on the current adjustment value and the previous adjustment value of the adjusting part, and the magnitude relationship between the current coating pressure value and the set coating pressure value includes: According to the magnitude relationship between the current coating pressure value and the set coating pressure value, assign a positive or negative sign to the current adjustment value, and use the sum or difference between the previous adjustment value and the current adjustment value of the adjusting part as the target execution value of the adjusting part.

[0009] As an optional embodiment, the step of assigning a positive or negative sign to the current adjustment value according to the magnitude relationship between the current coating pressure value and the set coating pressure value, and using the sum or difference between the previous adjustment value and the current adjustment value of the adjusting part as the target execution value of the adjusting part includes:; If the current coating pressure value is less than the set coating pressure value, set the current adjustment value to be positive, and use the sum of the previous adjustment value and the current adjustment value of the adjusting member as the target execution value of the adjusting member; If the current coating pressure value is greater than the set coating pressure value, set the current adjustment value to be negative, and use the difference between the previous adjustment value and the current adjustment value of the adjusting member as the target execution value of the adjusting member.

[0010] As an optional embodiment, step S3 includes: If the target execution value of the adjusting member is the sum of the previous adjustment value and the current adjustment value of the adjusting member, control to increase the stroke of the push rod of the adjusting member to adjust the amount of slurry returned from the flow distribution chamber to the return pipeline; If the target execution value of the adjusting member is the difference between the previous adjustment value and the current adjustment value of the adjusting member, control to decrease the stroke of the push rod of the adjusting member to adjust the amount of slurry returned from the flow distribution chamber to the return pipeline.

[0011] As an optional embodiment, after step S2 and before step S3, it further includes: Judge whether the target execution value is greater than the threshold; If the target execution value is greater than the threshold, use the threshold as the target execution value; and / or, The coating pressure value of the coating die head is the pressure value in the coating pipeline connecting the flow distribution chamber and the coating die head.

[0012] As an optional embodiment, before step S1, it further includes: Before the coating die head starts coating, determine the starting coating pressure value according to the set coating pressure value, and the starting coating pressure value is greater than the set coating pressure value; Set the coating pressure of the coating die head to the starting coating pressure value and maintain the starting coating pressure value for a set duration; After maintaining the set duration, set the coating pressure of the coating die head to the set coating pressure value and start the coating die head for coating.

[0013] The second aspect of the embodiments of the present application further provides a battery pole piece coating control system, including: A battery pole piece coating device, the battery pole piece coating device includes a feeding chamber, a flow distribution chamber, and a coating die head connected in series through a feeding pipeline in sequence, the flow distribution chamber is also connected in parallel with the feeding chamber through a return pipeline, and an adjusting member is connected to the return pipeline, and the adjusting member is used to adjust the amount of slurry returned from the flow distribution chamber to the return pipeline; A collection module, configured to obtain the current coating pressure value of the coating die head after the coating die head starts coating; A calculation module, configured to calculate a target execution value of the adjusting member based on a preset algorithm according to the current coating pressure value, a set coating pressure value, and the magnitude relationship between the two; A control device, configured to control the adjusting member to perform corresponding adjustment according to the target execution value of the adjusting member, so as to adjust the slurry return flow rate distributed from the flow distribution chamber to the return pipeline, and make the next coating pressure value of the coating die head approach the set coating pressure value.

[0014] As an optional embodiment, the feeding pipeline includes a conveying pipeline and a coating pipeline. The feeding chamber is connected to the flow distribution chamber through the conveying pipeline, and the flow distribution chamber and the coating die head are connected through the coating pipeline. The collection module is arranged on the coating pipeline for collecting the pressure in the coating pipeline.

[0015] As an optional embodiment, the adjusting member includes a valve body and a push rod. One end of the push rod is arranged inside the valve body, and the other end extends outside the valve body and is communicated with the return pipeline. The push rod can move in the direction perpendicular to the return port of the return pipeline under the action of a thrust force to increase or decrease the cross-section of the return port; the control device includes an output module and a control valve. The control valve is electrically connected to the output module and is connected to the valve body through an air pipe. The output module is configured to receive the target execution value and output the target execution value to the control valve. The control valve is configured to control the pressure in the air pipe according to the target execution value to control the stroke of the push rod.

[0016] A third aspect of the embodiments of the present application further provides a battery electrode sheet coating device, including: A processor; and A memory, on which executable code is stored. When the executable code is executed by the processor, the processor is caused to execute the method described above.

[0017] The technical solution provided by the present application may include the following beneficial effects: After the coating die head starts coating in this application, the current coating pressure value of the coating die head is obtained. According to the current coating pressure value and the set coating pressure value, the magnitude relationship between the two can be determined. Then, based on a preset algorithm, the target execution value of the adjusting member is calculated according to the current coating pressure value, the set coating pressure value, and their magnitude relationship, where the adjusting member is used to adjust the return flow rate of the slurry distributed to the return pipeline by the flow distribution chamber. The target execution value calculated by the preset algorithm is used to control the adjusting member to perform corresponding adjustment according to the current coating pressure value, the set coating pressure value, and their magnitude relationship. Exemplarily, the greater the return flow rate of the slurry distributed to the return pipeline by the adjusting member, the less the slurry distributed to the coating die head by the flow distribution chamber, and the lower the coating pressure of the coating die head; the smaller the return flow rate of the slurry distributed to the return pipeline, the greater the slurry distributed to the coating die head by the flow distribution chamber, and the greater the coating pressure of the coating die head. Therefore, this application can control the slurry flowing into the coating die head by adjusting the return flow rate of the slurry, thereby adjusting the coating pressure of the coating die head and keeping the coating pressure constant.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. Brief Description of the Drawings

[0019] By describing the exemplary embodiments of this application in more detail in conjunction with the drawings, the above and other objects, features, and advantages of this application will become more obvious. Among them, in the exemplary embodiments of this application, the same reference numerals generally represent the same components.

[0020] Figure 1 is a schematic flow chart of the battery electrode coating control method shown in the embodiments of this application; Figure 2 is another schematic flow chart of the battery electrode coating control method shown in the embodiments of this application; Figure 3 is a flow framework diagram of the battery electrode coating control method shown in the embodiments of this application; Figure 4 is a schematic structural diagram of the battery electrode coating control system shown in the embodiments of this application; Figure 5 is a schematic structural diagram of the battery electrode coating equipment shown in the embodiments of this application.

[0021] 1. Feeding pipeline; 10. Conveying pipeline; 11. Coating pipeline; 2. Feeding chamber; 3. Flow distribution chamber; 4. Coating die head; 5. Return pipeline; 6. Adjusting member; 60. Valve body; 61. Push rod; 7. Acquisition module; 8. Control device; 80. Output module; 81. Control valve; 82. Air pipe. Detailed Embodiments

[0022] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0023] The terms used in the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0024] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0025] In the related art, generally, an operator will manually adjust the opening of the reflux valve and finely adjust the pump speed of the feed pump according to experience to keep the coating pressure stable within a set pressure range.

[0026] However, this adjustment method completely relies on manual experience, and it is difficult to guarantee the debugging effect. Moreover, each time the product type is changed, manual re-debugging is required, which is extremely unfavorable to the production efficiency of the electrode sheet coating.

[0027] In view of the above problems, the embodiments of the present application provide a method for controlling the coating of battery electrode sheets, which can achieve constant-pressure feeding of the slurry through closed-loop control, realize the digitization and intelligentization of the electrode sheet production process, and improve the production efficiency.

[0028] The technical solutions of the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0029] Figure 1 It is a schematic flow chart of the method for controlling the coating of battery electrode sheets shown in the embodiments of the present application.

[0030] See Figure 1, an embodiment of the present application provides a method for controlling the coating of battery electrodes, which is applied to a battery electrode coating device. The battery electrode coating device includes a feeding chamber 2, a flow distribution chamber 3, and a coating die head 4 connected in series through a feeding pipeline 1 in sequence. The flow distribution chamber 3 is also connected in parallel with the feeding chamber 2 through a reflux pipeline 5, and an adjusting member 6 is connected to the reflux pipeline 5. The adjusting member 6 is used to adjust the slurry reflux amount distributed from the flow distribution chamber 3 into the reflux pipeline 5.

[0031] In the embodiment of the present application, the feeding chamber 2 stores slurry. A driving pump can be arranged on the feeding pipeline 1 between the feeding chamber 2 and the flow distribution chamber 3. The driving pump is used to transport the slurry in the feeding chamber 2 through the feeding pipeline 1 into the flow distribution chamber 3. The slurry in the flow distribution chamber 3 is then distributed into the coating die head 4, and the slurry sprays out from the lip of the coating die head 4 and is evenly coated on the copper foil or aluminum foil to form an electrode. During the coating process, not all of the slurry flowing out of the feeding pipeline 1 can be coated on the electrode, and the excess slurry in the flow distribution chamber 3 will flow back into the feeding chamber 2 through the reflux pipeline 5. The embodiment of the present application also sets an adjusting member 6 on the reflux pipeline 5. The adjusting member 6 is used to adjust the slurry reflux amount distributed from the flow distribution chamber 3 into the reflux pipeline 5. Specifically, the greater the slurry reflux amount distributed into the reflux pipeline 5, the less the slurry distributed from the flow distribution chamber 3 into the coating die head 4, and the smaller the coating pressure of the coating die head 4; the smaller the slurry reflux amount distributed into the reflux pipeline 5, the greater the slurry distributed from the flow distribution chamber 3 into the coating die head 4, and the greater the coating pressure of the coating die head 4. Therefore, the slurry flowing into the coating die head 4 can be controlled by adjusting the slurry reflux amount, thereby adjusting the coating pressure of the coating die head 4.

[0032] In order to achieve precise control of the coating pressure of the coating die head 4, the embodiment of the present application realizes the constant pressure adjustment of the slurry through closed-loop control. The method for controlling the coating of battery electrodes includes the following steps: S1. After the coating die head 4 starts coating, obtain the current coating pressure value of the coating die head 4.

[0033] In the embodiments of the present application, the moment when the lip of the coating die head 4 is opened can be used as the node for the coating die head 4 to start coating. During the coating process, various situations may cause the coating pressure to be unstable. For example, the motor pump speed fluctuates, the real-time liquid level height in the feeding chamber 2 is unstable, the air pressure in the air pipe fluctuates abnormally, the filter element is blocked by particles, etc. In the embodiments of the present application, the coating pressure value of the coating die head 4 can be obtained in real time according to a set frequency. For example, the coating pressure value of the coating die head 4 is obtained every 2 ms, and the coating pressure value of the coating die head 4 obtained at the current frequency is used as the current coating pressure value, the coating pressure value obtained 2 ms later is used as the next coating pressure value, the coating pressure value obtained 4 ms later is used as the next-next coating pressure value....... The coating pressure value obtained 2 ms before is used as the previous coating pressure value, the coating pressure value obtained 4 ms before is used as the previous-previous coating pressure value.......

[0034] S2. Based on a preset algorithm, calculate the target execution value of the adjusting member 6 according to the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two.

[0035] In the embodiments of the present application, the target execution value of the adjusting member 6 may refer to the target value for controlling the adjusting member 6 to perform corresponding adjustments. For example, the adjusting member 6 may include a valve body 60 and a push rod 61. One end of the push rod 61 is arranged inside the valve body 60, and the other end extends outside the valve body 60 and is connected to the return pipeline 5. The push rod 61 can move in the direction perpendicular to the return port of the return pipeline 5 under the action of a thrust force to increase or decrease the cross-section of the return port. The valve body 60 is also connected to the control valve 81 through an air pipe 82, and the control valve 81 is also electrically connected to the output module 80. The output module 80 is used to receive the target execution value and output the target execution value to the control valve 81. The control valve 81 is used to control the pressure in the air pipe 82 according to the target execution value to control the stroke of the push rod61.

[0036] Optionally, in the embodiments of the present application, the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5 can be adjusted by controlling the stroke of the push rod 61. The target execution value can refer to the stroke of the push rod 61, and the target execution value can be 0%, 20%, 40%, 80%, 100%, etc., or 0 mm, 1 mm, 5 mm, 10 mm, etc. The present application does not limit this. Alternatively, the target execution value can also refer to the pressure value in the air pipe 82 connected to the valve body 60. By controlling the pressure in the air pipe 82, the stroke of the push rod 61 is controlled. The target execution value can be 0 kPa, 100 kPa, 200 kPa, 500 kPa, etc. The present application does not limit this. Or, the target execution value can also refer to the analog quantity output by the output module 80 to the control valve 81. The target execution value can be 0, 1000, 5000, 10000, 20000, 30000, etc. The present application does not limit this. In the embodiments of the present application, it is preferred that the target execution value is the analog quantity output by the output module 80 to the control valve 81. In this way, the voltage change can be converted into a current change, and then the current change can be converted into an analog quantity to achieve the digital conversion and precise control of the voltage change.

[0037] In the embodiments of the present application, the target execution value of the adjusting member 6 is related to the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two. On the one hand, when calculating the target execution value of the adjusting member 6 using a preset algorithm, the current coating pressure value and the set coating pressure value may be required in the calculation formula. On the other hand, it is necessary to determine whether to increase or decrease the current control of the adjusting member 6 according to the magnitude relationship between the current coating pressure value and the set coating pressure value. Preferably, if the current coating pressure value is greater than the set coating pressure value, the adjusting member 6 is controlled to increase; if the current coating pressure value is less than the set coating pressure value, the adjusting member 6 is controlled to decrease.

[0038] In addition, in the embodiments of the present application, the set coating pressure value can be 300 kPa to 400 kPa, or can be set according to empirical values. The present application does not limit this.

[0039] S3. According to the target execution value of the adjusting member 66, control the adjusting member 6 to perform corresponding adjustments to adjust the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5, so that the next coating pressure value of the coating die head 4 is close to the set coating pressure value.

[0040] As can be seen from the above, in the embodiment of the present application, the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5 can be adjusted by controlling the stroke of the push rod 61. Taking the analog quantity output by the output module 80 to the control valve 81 as the target execution value as an example, the output module 80 can receive the analog quantity, convert the analog quantity into a target pressure value and output it to the control valve 81. The control valve 81 is used to control the pressure in the air pipe 82 according to the target pressure value to control the stroke of the push rod 61. Specifically, the analog quantity can be a value from 0 to 30000, corresponding to a pressure value of 0 kPa to 500 kPa.

[0041] In the embodiment of the present application, the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5 can be adjusted, and the coating amount of the slurry distributed by the flow distribution chamber 3 into the coating die head 4 can be correspondingly adjusted, so as to adjust the next coating pressure value of the coating die head 4, make the next coating pressure value of the coating die head 4 close to the set coating pressure value, and realize constant-pressure feeding coating.

[0042] S4. Obtain the next coating pressure value of the coating die head 4 and use it as the current coating pressure value, and repeat steps S2 to S3 until the coating of the battery electrode sheet is completed.

[0043] According to the set frequency, for example, after 2 ms, obtain the next coating pressure value of the coating die head 4 and use it as the current coating pressure value, repeat the calculation and adjustment of steps S2 to S3, complete the closed-loop control, and keep the coating pressure at each frequency within the range of the set coating pressure value, so as to realize the constancy of the coating pressure.

[0044] After the coating die head 4 starts coating in the embodiment of the present application, the current coating pressure value of the coating die head 4 is obtained. According to the current coating pressure value and the set coating pressure value, the magnitude relationship between the two can be determined; then, based on the preset algorithm, the target execution value of the adjusting member 6 is calculated according to the current coating pressure value, the set coating pressure value and the magnitude relationship between the two, where the adjusting member 6 is used to adjust the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5. The target execution value calculated by the preset algorithm is used to control the adjusting member 6 to perform corresponding adjustment according to the current coating pressure value, the set coating pressure value and the magnitude relationship between the two; exemplarily, the greater the return flow rate of the slurry distributed by the adjusting member 6 into the return pipeline 5, the less the slurry distributed by the flow distribution chamber 3 into the coating die head 4, and the smaller the coating pressure of the coating die head 4; the smaller the return flow rate of the slurry distributed into the return pipeline 5, the greater the slurry distributed by the flow distribution chamber 3 into the coating die head 4, and the greater the coating pressure of the coating die head 4. Therefore, in the embodiment of the present application, the coating pressure of the coating die head 4 can be adjusted by adjusting the return flow rate of the slurry, so as to keep the coating pressure constant.

[0045] Figure 2 It is another flow chart of the battery electrode sheet coating control method provided by the embodiment of the present application.

[0046] See Figure 2 Moreover, another process of the battery electrode coating control method is provided in the embodiment of the present application, which specifically includes the following steps: S10. After the coating die head 4 starts coating, obtain the current coating pressure value of the coating die head 4.

[0047] In the embodiment of the present application, the feeding pipeline 1 includes a conveying pipeline 10 and a coating pipeline 11. The feeding chamber 2 is connected to the flow distribution chamber 3 through the conveying pipeline 10, and the flow distribution chamber 3 and the coating die head 4 are connected through the coating pipeline 11. The coating pressure value of the coating die head 4 can be the pressure value in the coating pipeline 11.

[0048] Preferably, the pressure in the coating pipeline 11 can be collected by setting a pressure sensor on the coating pipeline 11, and the collected pressure value is used as the coating pressure value. The pressure sensor set on the coating pipeline 11 can convert the current change caused by the pressure change into a digital quantity and display it on a control system (such as a PLC). In this way, it can be seen from the display of the pressure sensor whether the coating pressure of the coating die head 4 reaches the set coating pressure under the current coating state of the coating die head 4.

[0049] S20. Obtain the previous coating pressure value and the penultimate coating pressure value of the coating die head 4, and calculate the difference between the penultimate coating pressure value and the previous coating pressure value of the coating die head 4, and use it as the first difference.

[0050] In the embodiment of the present application, the coating pressure value of the coating die head 4 can be obtained in real time at a set frequency. For example, the coating pressure value of the coating die head 4 is obtained every 2 ms, and the coating pressure value of the coating die head 4 obtained at the current frequency is used as the current coating pressure value tensionAVG, the coating pressure value obtained 2 ms later is used as the next coating pressure value, the coating pressure value obtained 4 ms later is used as the next-next coating pressure value....... The coating pressure value obtained 2 ms before is used as the previous coating pressure value UW_lastPV, and the coating pressure value obtained 4 ms before is used as the penultimate coating pressure value.......

[0051] Exemplarily, the first difference erlastPV = the penultimate coating pressure value - the previous coating pressure value UW_lastPV.

[0052] The data collected at each frequency and the calculated results can be stored and called, enabling the device to quickly switch product types, reducing the time for customers during product changeover, and improving production efficiency.

[0053] S21. Calculate the difference between the previous coating pressure value and the current coating pressure value of the coating die head 4, and use it as the second difference.

[0054] Exemplarily, the second difference pvk = the previous coating pressure value UW_lastPV - the current coating pressure value tensionAVG.

[0055] S22. Calculate the current adjustment value of the adjusting member 6 based on the first difference, the second difference, the current coating pressure value, and the set coating pressure value according to the first preset algorithm.

[0056] Exemplarily, the first preset algorithm can be a PID control algorithm, and the current adjustment value changeOUT of the adjusting member 6 can be calculated by the following formula: changeOUT=(kp×pvk+ki×(tensionSV-tensionAVG)+kd×(pvk-erlastPV)) / C Where, kp is the proportional coefficient, ki is the integral coefficient, kd is the differential coefficient, pvk is the second difference, tensionSV is the set coating pressure value, tensionAVG is the current coating pressure value, erlastPV is the first difference, and C is a constant.

[0057] Optionally, the first preset algorithm can be a PID control algorithm, and step S22 can include the following steps: S220. Set the proportional coefficient, the integral coefficient, and the differential coefficient.

[0058] In the embodiment of the present application, the PID control algorithm is a feedback control method combining proportional, integral, and differential links, which reduces the deviation between the actual coating pressure value and the set coating pressure value by dynamically adjusting the target execution value of the adjusting member 6. By setting an appropriate proportional coefficient kp, the fast response and fast correction of the control system can be achieved. By setting an appropriate integral coefficient ki, the cumulative historical error can be achieved to eliminate the steady-state error. By setting an appropriate differential coefficient kd, the change trend of the error can be predicted and overshoot can be suppressed.

[0059] In the embodiment of the present application, the proportional coefficient kp can be set to 300, the integral coefficient ki can be set to 10, and the differential coefficient kd can be set to 1. Alternatively, these three coefficients can be set to other empirical values according to the actual application scenario and production experience, and the present application does not limit this.

[0060] S221. Take the product of the second difference and the proportional coefficient as the proportional result.

[0061] Exemplarily, the proportional result = the proportional coefficient kp × the second difference pvk.

[0062] S222. Take the product of the difference between the current coating pressure value and the set coating pressure value and the integral coefficient as the integral result.

[0063] Exemplarily, the integration result = integration coefficient ki × (set coating pressure value tensionSV - current coating pressure value tensionAVG).

[0064] S223. Use the product of the difference between the second difference and the first difference and the differential coefficient as the differential result.

[0065] Exemplarily, the differential result = differential coefficient kd × (second difference pvk - first difference erlastPV).

[0066] S224. Accumulate the proportional result, the integration result, and the differential result as the current adjustment value of the adjusting member 6.

[0067] The current adjustment value changeOUT of the adjusting member 6 can be calculated by the following formula: changeOUT=(kp×pvk+ki×(tensionSV-tensionAVG)+kd×(pvk-erlastPV)) / C It should be noted in the specification that C in the formula is a constant. The magnitude of C can represent the adjustment degree of the current adjustment value changeOUT. The larger the C value, the smaller the adjustment degree, and the higher the adjustment accuracy. C can be set to 2000 or other values that can improve the adjustment accuracy. This application does not make any limitations on this.

[0068] S23. Based on the current adjustment value and the previous adjustment value of the adjusting member 6, and the magnitude relationship between the current coating pressure value and the set coating pressure value, calculate the target execution value of the adjusting member 6 based on the second preset algorithm.

[0069] In the embodiments of this application, the previous adjustment value of the adjusting member 6 can represent the adjustment value calculated in the previous frequency. Its calculation method is the same as that of the current adjustment value of the adjusting member 6, and this application will not elaborate here.

[0070] Based on the magnitude relationship between the current coating pressure value and the set coating pressure value, it can be determined whether the target execution value of the adjusting member 6 increases or decreases based on the previous adjustment value. Specifically, if the current coating pressure value is less than the set coating pressure value, the sum of the previous adjustment value and the current adjustment value of the adjusting member 6 can be used as the target execution value of the adjusting member 6. If the current coating pressure value is greater than the set coating pressure value, the difference between the previous adjustment value and the current adjustment value of the adjusting member 6 can be used as the target execution value of the adjusting member 6.

[0071] In the embodiments of this application, step S23 may include the following steps: S230. Based on the magnitude relationship between the current coating pressure value and the set coating pressure value, assign a positive or negative sign to the current adjustment value, and use the sum or difference of the previous adjustment value and the current adjustment value of the adjusting member 6 as the target execution value of the adjusting member 6.

[0072] In the embodiment of the present application, the second preset algorithm may be as follows: lastOUT = lastOUT’ + (changeOUT) × i Wherein, lastOUT is the target execution value, lastOUT’ is the previous adjustment value, changeOUT is the current adjustment value, and i is an imaginary value.

[0073] If the current coating pressure value is less than the set coating pressure value, the current adjustment value can be set to be positive. For example, the current adjustment value can be given a positive sign by setting i to +1, and the sum of the current adjustment value and the previous adjustment value of the adjusting member 6 is used as the target execution value of the adjusting member 6; and if the current coating pressure value is greater than the set coating pressure value, the current adjustment value can be set to be negative. For example, the current adjustment value can be given a negative sign by setting i to -1, and the difference between the previous adjustment value and the current adjustment value of the adjusting member 6 is used as the target execution value of the adjusting member 6. Vice versa, that is, if the current coating pressure value is less than the set coating pressure value, the current adjustment value can be set to be negative, and if the current coating pressure value is greater than the set coating pressure value, the current adjustment value can be set to be positive. The present application does not limit the correspondence between the magnitude relationship between the current coating pressure value and the set coating pressure value and the positive or negative of the current adjustment value, as long as the positive or negative of the current adjustment value can be adjusted according to the magnitude relationship between the current coating pressure value and the set coating pressure value.

[0074] In the embodiment of the present application, by setting an imaginary value in the second preset algorithm, the positive or negative of the current adjustment value is adjusted to control the calculation result of the target execution value to increase or decrease, so as to correspond to the magnitude relationship between the current coating pressure value and the set coating pressure value.

[0075] It should be noted that the output value of the target execution value is PIDout, and PIDout = lastOUT. When the coating is started, lastOUT’ is the initial setting value, and PIDout = lastOUT’. For example, lastOUT’ can be 18000, corresponding to a coating pressure value of 300 kPa.

[0076] The embodiment of the present application details step S230 in one way: S2301. If the current coating pressure value is less than the set coating pressure value, set the current adjustment value to be positive, and use the sum of the previous adjustment value and the current adjustment value of the adjusting member 6 as the target execution value of the adjusting member 6.

[0077] If the current coating pressure value is less than the set coating pressure value, it indicates that the current coating pressure value is small and the coating pressure needs to be increased. Then, the virtual value i in the second preset algorithm can be set to a positive value, such as +1. The corresponding second preset algorithm in this case can be lastOUT = lastOUT’ + changeOUT. The larger the calculated target execution value is. Further, the stroke of the push rod 61 of the adjusting member 6 can be increased, controlling the reduction or increase of the slurry return flow rate from the flow distribution chamber 3 into the return pipeline 5, and the corresponding increase or decrease of the slurry coating amount from the flow distribution chamber 3 into the coating die head 4, so as to increase or decrease the coating pressure value.

[0078] S2302. If the current coating pressure value is greater than the set coating pressure value, set the current adjustment value to negative, and use the difference between the previous adjustment value and the current adjustment value of the adjusting member 6 as the target execution value of the adjusting member 6.

[0079] If the current coating pressure value is greater than the set coating pressure value, it indicates that the current coating pressure value is large and the coating pressure needs to be reduced. Then, the virtual value i in the second preset algorithm can be set to a negative value, such as -1. The corresponding second preset algorithm in this case can be lastOUT = lastOUT’ - changeOUT. The smaller the calculated target execution value is. Further, the stroke of the push rod 61 of the adjusting member 6 can be reduced, controlling the increase or decrease of the slurry return flow rate from the flow distribution chamber 3 into the return pipeline 5, and the corresponding decrease or increase of the slurry coating amount from the flow distribution chamber 3 into the coating die head 4, so as to reduce or increase the coating pressure value.

[0080] S30. If the target execution value of the adjusting member 6 is the sum of the previous adjustment value and the current adjustment value of the adjusting member 6, control the stroke of the push rod 61 of the adjusting member 6 to be increased to adjust the slurry return flow rate from the flow distribution chamber 3 into the return pipeline 5.

[0081] Exemplarily, if the target execution value of the adjusting member 6 is the sum of the previous adjustment value and the current adjustment value of the adjusting member 6, control the stroke of the push rod 61 of the adjusting member 6 to become larger. According to actual requirements, the slurry return flow rate from the flow distribution chamber 3 into the return pipeline 5 can be correspondingly controlled to be reduced, and the slurry coating amount from the flow distribution chamber 3 into the coating die head 4 can be controlled to be increased, so as to increase the coating pressure value. Conversely, it can also be that the stroke of the push rod 61 of the adjusting member 6 becomes larger, correspondingly controlling the increase of the slurry return flow rate from the flow distribution chamber 3 into the return pipeline 5, and the decrease of the slurry coating amount from the flow distribution chamber 3 into the coating die head 4, so as to reduce the coating pressure value. This application does not limit the relationship between the change in the stroke of the push rod 61 of the adjusting member 6 and the size of the slurry return flow rate from the flow distribution chamber 3 into the return pipeline 5, as long as the change in the stroke of the push rod 61 of the adjusting member 6 can be used to adjust the size of the slurry return flow rate.

[0082] S31. If the target execution value of the adjusting member 6 is the difference between the previous adjustment value and the current adjustment value of the adjusting member 6, control the stroke of the push rod 61 of the adjusting member 6 to be reduced, so as to adjust the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5.

[0083] Exemplarily, if the target execution value of the adjusting member 6 is the difference between the previous adjustment value and the current adjustment value of the adjusting member 6, control the stroke of the push rod 61 of the adjusting member 6 to become smaller. According to actual requirements, correspondingly control the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5 to be increased, and control the coating amount of the slurry distributed by the flow distribution chamber 3 into the coating die head 4 to be reduced, so as to reduce the coating pressure value. On the contrary, it can also be that the stroke of the push rod 61 of the adjusting member 6 becomes smaller, correspondingly control the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5 to be reduced, and control the coating amount of the slurry distributed by the flow distribution chamber 3 into the coating die head 4 to be increased, so as to reduce the coating pressure value. The present application does not limit the corresponding relationship between the change in the stroke of the push rod 61 of the adjusting member 6 and the size of the return flow rate of the slurry distributed by the flow distribution chamber 3 into the return pipeline 5, as long as the change in the stroke of the push rod 61 of the adjusting member 6 can be used to adjust the size of the return flow rate of the slurry.

[0084] Preferably, before step S10, the following steps are further included: S01. Before the coating die head 4 starts coating, determine the starting coating pressure value according to the set coating pressure value, and the starting coating pressure value is greater than the set coating pressure value.

[0085] S02. Set the coating pressure of the coating die head 4 to the starting coating pressure value and maintain the starting coating pressure value for a set duration.

[0086] S03. After the set duration, set the coating pressure of the coating die head 4 to the set coating pressure value and start the coating die head 4 for coating.

[0087] When the coating die head 4 starts coating, the lip of the coating die head 4 instantaneously discharges material for coating, and the film cavity instantaneously decompresses at this time, and the coating pressure will drop significantly, resulting in unstable discharge flow rate. In the embodiment of the present application, by setting the starting coating pressure value and performing a time-delay pressure-holding treatment, the coating pressure that drops significantly due to the instantaneous discharge and coating of the lip of the starting coating die head 4 can be effectively offset. Through this starting pressure-holding treatment, the production coating pressure can be effectively stabilized within the range of the set coating pressure value.

[0088] In the embodiment of the present application, the starting coating pressure value can use the set coating pressure value as a reference value, and in combination with production experience, the starting coating pressure value can be set to 110% of the set coating pressure value or other empirical values, and a pressure-holding delay of a set duration, such as 1 s, is performed with this starting coating pressure value. After the pressure-holding ends, set the coating pressure of the coating die head 4 to the set coating pressure value, and then start the coating die head 4 for coating.

[0089] Preferably, after step S23 and before step S30, the following steps are further included: Determine whether the target execution value is greater than the threshold.

[0090] Due to the influence of the working upper limits of various components in the coating device, such as the upper limit of the pump speed of the motor pump, there is also an upper limit for the adjustment of the coating pressure. Adjusting the coating pressure according to the calculated target execution value may exceed the adjustment upper limit. Therefore, in the embodiments of the present application, a threshold is set to prevent the target execution value from being too large and affecting the normal operation of the equipment.

[0091] If the target execution value is greater than the threshold, then use the threshold as the target execution value If the target execution value is greater than the threshold, adjusting according to the target execution value may cause problems such as equipment failure or damage. In the embodiments of the present application, by setting the threshold and setting the target execution value greater than the threshold to the threshold, the normal operation of the equipment can be protected.

[0092] In addition, the threshold in the embodiments of the present application can be set according to the upper limit value or empirical value of the equipment. For example, the threshold can be 30000, and the present application does not make any limitations in this regard.

[0093] See Figure 3 , for a description of the complete control method of the embodiments of the present application.

[0094] S300. Set parameters, including establishing a control system database, and establishing 6 arrays in the PLC control system, which are respectively used for 1. The set value of the screw pump speed; 2. The set coating pressure value; 3. The start coating pressure value; 4. The proportional coefficient; 5. The integral coefficient; 6. The differential coefficient.

[0095] S301. Start coating, including turning on the coating die head 4, but the lip is not opened.

[0096] S302. Start coating pressure holding, including performing a pressure holding process on the start coating pressure before the lip is opened, using the set coating pressure value as the reference value. According to the production verification results in the production workshop, the start coating pressure value can be 110% of the set coating pressure value, and a pressure holding delay of 1 s is performed with this start coating pressure value.

[0097] S303. Pressure detection, including obtaining the current coating pressure value of the coating die head 4 after the lip of the coating die head 4 is opened S304. PID control, including calculating the target execution value of the adjusting member 6 based on a preset algorithm according to the current coating pressure value, the set coating pressure value, and their magnitude relationship, and converting the target execution value into a target pressure value for output.

[0098] S305. Electrical proportional valve control, which includes receiving a target pressure value and controlling the pressure in the air pipe 82 according to the target pressure value to control the stroke of the pneumatic cut-off valve.

[0099] S306. Pneumatic cut-off valve control, which includes the push rod of the pneumatic cut-off valve moving in the direction perpendicular to the return port of the return pipe 5 under the action of air pressure to increase or decrease the cross-section of the return port, thereby changing the return flow rate.

[0100] After the control of step S306 ends, it goes to step S303 for closed-loop control until the coating ends.

[0101] Corresponding to the foregoing embodiment of the application function implementation method, the present application also provides a battery electrode coating control system, an electronic device, and corresponding embodiments.

[0102] Figure 4 It is a schematic structural diagram of the battery electrode coating control system shown in the embodiment of the present application.

[0103] See Figure 4 , the embodiment of the present application also provides a battery electrode coating control system, which includes a battery electrode coating device, a collection module 7, a calculation module, and a control device 8. The battery electrode coating device includes a feeding chamber 2, a flow distribution chamber 3, and a coating die head 4 connected in series through a feeding pipe 1 in sequence. The flow distribution chamber 3 is also connected in parallel with the feeding chamber 2 through a return pipe 5, and an adjusting member 6 is connected to the return pipe 5. The adjusting member 6 is used to adjust the return flow rate of the slurry distributed from the flow distribution chamber 3 into the return pipe 5. The collection module 7 is used to obtain the current coating pressure value of the coating die head 4 after the coating die head 4 starts coating. The calculation module is used to calculate the target execution value of the adjusting member 6 based on a preset algorithm according to the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two. The control device 8 is used to control the adjusting member 6 to perform corresponding adjustments according to the target execution value of the adjusting member 6 to increase or decrease the return flow rate of the slurry distributed from the flow distribution chamber 3 into the return pipe 5, so that the next coating pressure value of the coating die head 4 is close to the set coating pressure value.

[0104] In the embodiment of the present application, the feeding chamber 2 stores slurry. A driving pump can be provided on the feeding pipe 1 between the feeding chamber 2 and the flow distribution chamber 3. The driving pump is used to transport the slurry in the feeding chamber 2 through the feeding pipe 1 into the flow distribution chamber 3, and the slurry in the flow distribution chamber 3 is redistributed into the coating die head 4. The slurry sprays out from the lip of the coating die head 4 and is evenly coated on the copper foil or aluminum foil to form an electrode. During the coating process, not all of the slurry flowing out of the feeding pipe 1 can be coated on the electrode, and the excess slurry in the flow distribution chamber 3 will flow back into the feeding chamber 2 through the return pipe 5.

[0105] In the embodiment of the present application, after the coating die head 4 starts coating, the acquisition module 7 acquires the current coating pressure value of the coating die head 4. According to the current coating pressure value and the set coating pressure value, the magnitude relationship between the two can be determined. The acquisition module 7 transmits the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two to the input module. Then, the calculation module calculates the target execution value of the adjusting member 6 based on the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two, and based on a preset algorithm. The adjusting member 6 is used to adjust the return flow rate of the slurry distributed to the return pipeline 5 by the flow distribution chamber 3. The target execution value calculated by the preset algorithm enables the control device 8 to control the adjusting member 6 to perform corresponding adjustment according to the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two. Exemplarily, the larger the return flow rate of the slurry distributed to the return pipeline 5 by the adjusting member 6, the less the slurry distributed to the coating die head 4 by the flow distribution chamber 3, and the lower the coating pressure of the coating die head 4; the smaller the return flow rate of the slurry distributed to the return pipeline 5, the more the slurry distributed to the coating die head 4 by the flow distribution chamber 3, and the higher the coating pressure of the coating die head 4. Therefore, the embodiment of the present application can control the slurry flowing into the coating die head 4 by adjusting the return flow rate of the slurry, thereby adjusting the coating pressure of the coating die head 4 and keeping the coating pressure constant.

[0106] Optionally, the feeding pipeline 1 includes a conveying pipeline 10 and a coating pipeline 11. The feeding chamber 2 is connected to the flow distribution chamber 3 through the conveying pipeline 10, and the flow distribution chamber 3 and the coating die head 4 are connected through the coating pipeline 11. The acquisition module 7 is arranged on the coating pipeline 11 and is used to acquire the pressure in the coating pipeline 11.

[0107] In the embodiment of the present application, the slurry in the feeding chamber 2 can be first conveyed to the flow distribution chamber 3 through the conveying pipeline 10. After the flow distribution chamber 3 distributes the coating amount and the return flow rate of the slurry, the flow distribution chamber 3 conveys the slurry to the coating die head 4 through the coating pipeline 11, so that the slurry conveyed to the coating die head 4 can be ejected from the lip opening at the set coating pressure value for coating. The acquisition module 7 is arranged on the coating pipeline 11 and is used to acquire the pressure in the coating pipeline 11 and use it as the current coating pressure value. Since the coating pipeline 11 is communicated with the coating die head 4, when the lip opening of the coating die head 4 is opened for coating, the pressure values in the coating pipeline 11 and the coating die head 4 are basically the same. Therefore, acquiring the pressure in the coating pipeline 11 is equivalent to the pressure in the coating die head 4, and the acquisition module 7 arranged on the coating pipeline 11 is more stable and will not be affected by the coating work of the coating die head 4, and the acquired pressure value is more accurate.

[0108] In addition, the acquisition module 7 in the embodiment of the present application can be a pressure sensor or other acquisition instruments that can be converted into pressure values, and the present application does not limit this.

[0109] Optionally, the adjusting member 6 includes a valve body 60 and a push rod 61. One end of the push rod 61 is disposed inside the valve body 60, and the other end extends outside the valve body 60 and is connected to the reflux pipeline 5. The push rod 61 can move in a direction perpendicular to the reflux port of the reflux pipeline 5 under the action of a thrust force to increase or decrease the cross-section of the reflux port. The control device 8 includes an output module 80 and a control valve 81. The control valve 81 is electrically connected to the output module 80 and is connected to the valve body 60 through an air pipe 82. The output module 80 is configured to receive a target execution value and convert the target execution value into a target pressure value for output to the control valve 81. The control valve 81 is configured to control the pressure in the air pipe 82 according to the target pressure value to control the stroke of the push rod 61.

[0110] In the embodiment of the present application, the adjusting member 6 can be a pneumatic stop valve. The shape of one end of the push rod 61 disposed inside the valve body 60 can match the cross-sectional shape of the valve body 60, such as circular, square, etc. One end of the push rod 61 extending outside the valve body 60 can be a cylinder. Exemplarily, the longer the depth of this end extending into the reflux pipeline 5, the smaller the cross-section of the reflux port of the reflux pipeline 5, and the depth of this end extending into the reflux pipeline 5 is affected by the magnitude of the thrust force of the push rod 61. The greater the thrust force, the longer the depth of this end extending into the reflux pipeline 5.

[0111] In the embodiment of the present application, the control valve 81 can be an electro-pneumatic proportional valve. The electro-pneumatic proportional valve has three interfaces, which are respectively connected to the output module 80, the adjusting member 6, and the air source. The output module 80 is configured to receive a target execution value and convert the target execution value into a target pressure value for output to the electro-pneumatic proportional valve. The electro-pneumatic proportional valve is configured to control the pressure of the gas output from the air source according to the target pressure value to control the stroke of the push rod 61, thereby controlling the depth of the push rod 61 extending into the reflux pipeline 5 to increase or decrease the reflux amount of the slurry.

[0112] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment related to the method, and will not be elaborated here in detail.

[0113] Figure 5 It is a schematic structural diagram of a battery electrode coating device shown in an embodiment of the present application.

[0114] See Figure 5 , the battery electrode coating device 500 includes a memory 510 and a processor 520.

[0115] The processor 520 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0116] The memory 510 may include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage devices. Among them, the ROM may store static data or instructions required by the processor 520 or other modules of the computer. The permanent storage device may be a read-write storage device. The permanent storage device may be a non-volatile storage device that does not lose the stored instructions and data even when the computer is powered off. In some embodiments, the permanent storage device uses a mass storage device (such as a magnetic or optical disk, flash memory) as the permanent storage device. In some other embodiments, the permanent storage device may be a removable storage device (such as a floppy disk, optical drive). The system memory may be a read-write storage device or a volatile read-write storage device, such as dynamic random access memory. The system memory may store some or all of the instructions and data required by the processor during operation. In addition, the memory 510 may include any combination of computer-readable storage media, including various types of semiconductor storage chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and magnetic disks and / or optical disks may also be used. In some embodiments, the memory 510 may include a removable storage device that is readable and / or writable, such as a compact disc (CD), read-only digital versatile disc (such as DVD-ROM, dual-layer DVD-ROM), read-only Blu-ray disc, super density disc, flash memory card (such as SD card, min SD card, Micro-SD card, etc.), magnetic floppy disk, etc. The computer-readable storage medium does not include carrier waves and instantaneous electronic signals transmitted wirelessly or wired.

[0117] An executable code is stored on the memory 510, and when the executable code is processed by the processor 520, it may cause the processor 520 to execute some or all of the methods described above.

[0118] In addition, the method according to the present application can also be implemented as a computer program or a computer program product, which includes computer program code instructions for performing some or all of the steps in the above method of the present application.

[0119] Alternatively, the present application can also be implemented as a computer-readable storage medium (or a non-transitory machine-readable storage medium or a machine-readable storage medium), on which executable code (or a computer program or computer instruction code) is stored. When the executable code (or the computer program or computer instruction code) is executed by a processor of an electronic device (or a server, etc.), the processor is caused to execute some or all of the steps of the above method according to the present application.

[0120] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application or the improvement of the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the embodiments disclosed herein.

Claims

1. A method for controlling the coating of a battery electrode sheet, characterized in that, Including: S1. After the coating die starts coating, obtain the current coating pressure value of the coating die; S2. Based on a preset algorithm, calculate the target execution value of the adjusting part according to the current coating pressure value, the set coating pressure value, and the magnitude relationship between the two; S3. According to the target execution value of the adjusting part, control the adjusting part to perform corresponding adjustments to adjust the slurry return flow rate distributed from the flow distribution chamber into the return pipeline, so that the next coating pressure value of the coating die is close to the set coating pressure value; S4. Obtain the next coating pressure value of the coating die and use it as the current coating pressure value, and repeat steps S2 to S3 until the coating of the battery electrode sheet is completed.

2. The method according to claim 1, wherein The step S2 includes: Obtain the upper-upper coating pressure value and the previous coating pressure value of the coating die, and calculate the difference between the upper-upper coating pressure value and the previous coating pressure value of the coating die, and use it as the first difference; Calculate the difference between the previous coating pressure value and the current coating pressure value of the coating die, and use it as the second difference; Based on the first preset algorithm, calculate the current adjustment value of the adjusting part according to the first difference, the second difference, the current coating pressure value, and the set coating pressure value; Based on the second preset algorithm, calculate the target execution value of the adjusting part according to the current adjustment value and the previous adjustment value of the adjusting part, and the magnitude relationship between the current coating pressure value and the set coating pressure value.

3. The method according to claim 2, wherein The first preset algorithm is a PID control algorithm. The calculating the current adjustment value of the adjusting part based on the first difference, the second difference, the current coating pressure value, and the set coating pressure value according to the first preset algorithm includes: Set the proportional coefficient, integral coefficient, and differential coefficient; Use the product of the second difference and the proportional coefficient as the proportional result; Use the product of the difference between the current coating pressure value and the set coating pressure value and the integral coefficient as the integral result; Use the product of the difference between the second difference and the first difference and the differential coefficient as the differential result; Accumulate the proportional result, the integral result, and the differential result as the current adjustment value of the adjusting part.

4. The method according to claim 2, wherein The calculating the target execution value of the adjusting part based on the second preset algorithm according to the current adjustment value and the previous adjustment value of the adjusting part, and the magnitude relationship between the current coating pressure value and the set coating pressure value includes: According to the magnitude relationship between the current coating pressure value and the set coating pressure value, assign a positive or negative sign to the current adjustment value, and use the sum or difference between the previous adjustment value and the current adjustment value of the adjusting part as the target execution value of the adjusting part.

5. The method according to claim 4, characterized in that, The according to the magnitude relationship between the current coating pressure value and the set coating pressure value, assign a positive or negative sign to the current adjustment value, and use the sum or difference between the previous adjustment value and the current adjustment value of the adjusting part as the target execution value of the adjusting part includes: If the current coating pressure value is less than the set coating pressure value, set the current adjustment value to be positive, and use the sum of the previous adjustment value and the current adjustment value of the adjusting part as the target execution value of the adjusting part; If the current coating pressure value is greater than the set coating pressure value, set the current adjustment value to be negative, and use the difference between the previous adjustment value and the current adjustment value of the adjusting member as the target execution value of the adjusting member.

6. The method according to claim 5, wherein The step S3 includes: If the target execution value of the adjusting member is the sum of the previous adjustment value and the current adjustment value of the adjusting member, control to increase the stroke of the push rod of the adjusting member to adjust the slurry return flow rate distributed by the flow distribution chamber into the return pipeline; If the target execution value of the adjusting member is the difference between the previous adjustment value and the current adjustment value of the adjusting member, control to decrease the stroke of the push rod of the adjusting member to adjust the slurry return flow rate distributed by the flow distribution chamber into the return pipeline.

7. The method according to claim 1, characterized in that After the step S2 and before the step S3, it further includes: Judge whether the target execution value is greater than the threshold; If the target execution value is greater than the threshold, use the threshold as the target execution value; and / or, The coating pressure value of the coating die head is the pressure value in the coating pipeline connecting the flow distribution chamber and the coating die head; and / or, Before the step S1, it further includes: Before the coating die head starts coating, determine the starting coating pressure value according to the set coating pressure value, and the starting coating pressure value is greater than the set coating pressure value; Set the coating pressure of the coating die head to the starting coating pressure value and maintain the starting coating pressure value for a set time period; After maintaining the set time period, set the coating pressure of the coating die head to the set coating pressure value and start the coating die head for coating.

8. A battery electrode coating control system, characterized in that, It includes: A battery pole piece coating device, which includes a feeding chamber, a flow distribution chamber and a coating die head connected in series through a feeding pipeline in sequence. The flow distribution chamber is also connected in parallel with the feeding chamber through a return pipeline, and an adjusting member is connected to the return pipeline. The adjusting member is used to adjust the slurry return flow rate distributed by the flow distribution chamber into the return pipeline; An acquisition module, which is used to obtain the current coating pressure value of the coating die head after the coating die head starts coating; A calculation module, which is used to calculate the target execution value of the adjusting member based on a preset algorithm according to the current coating pressure value, the set coating pressure value and their magnitude relationship; A control device, which is used to control the adjusting member to perform corresponding adjustments according to the target execution value of the adjusting member to adjust the slurry return flow rate distributed by the flow distribution chamber into the return pipeline, so that the next coating pressure value of the coating die head is close to the set coating pressure value.

9. The system according to claim 8, wherein The feeding pipeline includes a conveying pipeline and a coating pipeline. The feeding chamber is connected to the flow distribution chamber through the conveying pipeline, and the flow distribution chamber and the coating die head are connected through the coating pipeline. The acquisition module is arranged on the coating pipeline to collect the pressure in the coating pipeline; and / or, The adjusting member includes a valve body and a push rod. One end of the push rod is disposed inside the valve body, and the other end extends outside the valve body and is communicatively connected to the reflux pipeline. The push rod can move in a direction perpendicular to the reflux port of the reflux pipeline under the action of a thrust force to increase or decrease the cross-section of the reflux port. The control device includes an output module and a control valve. The control valve is electrically connected to the output module and is connected to the valve body through an air pipe. The output module is configured to receive the target execution value and output the target execution value to the control valve. The control valve is configured to control the pressure in the air pipe according to the target execution value to control the stroke of the push rod.

10. A battery electrode sheet coating device, characterized in that, Comprising: a processor; and a memory having executable code stored thereon, which when executed by the processor causes the processor to perform the method according to any one of claims 1-7.

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