Rolling control method and system for battery pole piece and storage medium

Abstract

The invention relates to the technical field of roller press control, in particular to a rolling control method and system for a battery pole piece and a storage medium, and aims at solving the problem that the thickness of a rolled battery pole piece is not uniform due to the fact that the thickness of an incoming material is not uniform. The rolling control method for the battery pole piece comprises the steps that the first thickness of the battery pole piece before rolling and the second thickness of the battery pole piece after rolling are obtained, a current rolling parameter is determined by adopting a closed-loop control algorithm based on the second thickness, and compensation adjustment is conducted on the current rolling parameter based on the first thickness, and controlling the rolling operation of the battery pole piece according to the compensated and adjusted rolling parameters. The purpose of improving the consistency of the rolling thickness of the battery pole piece is achieved, the yield of the manufacturing process of the battery pole piece is improved, scrapping is reduced, and finally the overall yield of the battery is improved.

Description

Technical Field

[0001] The present application relates to the field of roller press control technology, and in particular to a roller press control method, system and storage medium for a battery pole piece. Background Art

[0002] At present, in the rolling process of lithium battery production, a thickness gauge is usually placed behind the roller press. The roller gap of the roller press is adjusted through a closed-loop system to control the thickness of the electrode. However, this closed-loop control has a certain lag. When the thickness of the incoming material is different, the thickness of the electrode after rolling is uneven, which affects the reliability of subsequent processes and cannot meet production requirements.

[0003] Accordingly, the art needs a new rolling control solution for battery pole sheets to solve the above problems. Summary of the invention

[0004] In order to overcome the above-mentioned defects, the present application is proposed to solve or at least partially solve the technical problem that the uneven thickness of the battery pole sheet after rolling is caused by the uneven thickness of the incoming material.

[0005] In a first aspect, a rolling control method for a battery electrode is provided, comprising: obtaining a first thickness of the battery electrode before rolling and a second thickness of the battery electrode after rolling; determining a current rolling parameter based on the second thickness using a closed-loop control algorithm; compensating and adjusting the current rolling parameter based on the first thickness; and controlling the rolling operation of the battery electrode according to the compensated and adjusted rolling parameter.

[0006] In a technical solution of the above-mentioned battery pole sheet rolling control method, the current rolling parameters are determined based on the second thickness using a closed-loop control algorithm, including: obtaining a preset second target value of the battery pole sheet after rolling; and calculating the current rolling parameters based on the difference between the second thickness and the second target value using a closed-loop control algorithm.

[0007] In a technical solution of the above-mentioned rolling control method of the battery electrode, the compensating adjustment of the current rolling parameter based on the first thickness includes: obtaining a preset first target value of the battery electrode before rolling and a thickness compensation function, wherein the thickness compensation function is a correspondence between the change in the thickness of the battery electrode and the change in the rolling parameter obtained through analysis; determining the change in the rolling parameter corresponding to the difference between the first thickness and the first target value according to the thickness compensation function; and taking the sum of the change in the rolling parameter and the current rolling parameter as the compensated and adjusted rolling parameter.

[0008] In a technical solution of the above-mentioned battery pole sheet rolling control method, the rolling operation of the battery pole sheet is controlled according to the compensated and adjusted rolling parameters, including: when the collection position of the first thickness on the battery pole sheet reaches the rolling area, the rolling operation of the battery pole sheet is controlled based on the compensated and adjusted rolling parameters.

[0009] In a technical solution of the above-mentioned rolling control method of the battery pole sheet, the first thickness includes the average value of the thickness of multiple sampling points of the battery pole sheet that has not passed through the rolling area within a preset sampling period; the second thickness includes the average value of the thickness of multiple sampling points of the battery pole sheet that has passed through the rolling area within a preset sampling period.

[0010] In a technical solution of the above-mentioned rolling control method of the battery pole piece, the rolling parameters include the rolling pressure value, and the method further includes: storing the compensated and adjusted pressure value corresponding to the first thickness collection position on the battery pole piece during the rolling process.

[0011] In a technical solution of the above-mentioned rolling control method of the battery pole piece, the method further includes: when the rolling parameter after the compensation adjustment is greater than a preset safety threshold, an alarm is issued and the rolling operation of the battery pole piece is stopped.

[0012] In a second aspect, a rolling control system for a battery electrode is provided, comprising: a thickness acquisition module, used to obtain a first thickness of the battery electrode before rolling and a second thickness after rolling; a parameter determination module, which determines a current rolling parameter based on the second thickness using a closed-loop control algorithm; a compensation adjustment module, which compensates and adjusts the current rolling parameter based on the first thickness; and a rolling control module, which controls the rolling operation of the battery electrode according to the compensated and adjusted rolling parameter.

[0013] In a technical solution of the above-mentioned battery electrode rolling control system, the thickness acquisition module includes: a first thickness gauge and a second thickness gauge, wherein the first thickness gauge is used to obtain a first thickness of the battery electrode before being rolled, and the second thickness gauge is used to obtain a second thickness of the battery electrode after being rolled, wherein the distance between the first thickness gauge and the rolling area is equal to the distance between the second thickness gauge and the rolling area.

[0014] In a third aspect, a computer-readable storage medium is provided, in which a plurality of program codes are stored, wherein the program codes are suitable for being loaded and run by a processor to execute the method in the above-mentioned first aspect or any corresponding technical solution thereof.

[0015] The above one or more technical solutions of the present application have at least one or more of the following beneficial effects:

[0016] In the technical solution for implementing the present application, a closed-loop control algorithm is used to determine the current rolling parameters based on the second thickness of the battery pole sheet after rolling, and the current rolling parameters are compensated and adjusted based on the first thickness of the battery pole sheet before rolling. The rolling operation of the battery pole sheet is controlled according to the compensated and adjusted rolling parameters, thereby achieving the purpose of improving the consistency of the rolled thickness of the battery pole sheet, which is beneficial to improving the yield of the battery pole sheet manufacturing process, reducing scrap, and ultimately improving the overall yield of the battery.

[0017] In the technical solution for implementing the present application, since the closed-loop control adjustment has a lag and it is difficult to accurately control the adjustment in one go, the present application utilizes a closed-loop control algorithm to calculate the current rolling parameters based on the difference between the second thickness and the second target value, and determines the rolling parameter change corresponding to the difference between the first thickness and the first target value based on the thickness compensation function, and uses the rolling parameter change to compensate for the current rolling parameters, thereby effectively reducing the number of rolling adjustments and the adjustment time, and solving the problem of uneven rolling thickness of the battery pole piece due to changes in the thickness of the incoming material.

[0018] In the technical solution for implementing the present application, the first thickness and the second thickness are calculated using the average thickness of multiple sampling points of the battery pole piece within a preset sampling period, thereby achieving the purpose of improving the accuracy of thickness collection and compensation, and achieving the effect of improving the pole piece rolling control accuracy and rolling thickness uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The disclosure of the present application will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present application. Among them:

[0020] Figure 1 It is a schematic flow chart of the main steps of a rolling control method for a battery pole piece according to an embodiment of the present application;

[0021] Figure 2 It is a schematic diagram of the main structural block diagram of a rolling control system for a battery pole piece according to an embodiment of the present application;

[0022] Figure 3 is a schematic diagram of a rolling process of a battery pole piece according to an embodiment of the present application;

[0023] Figure 4 It is a schematic diagram of the thickness closed-loop control of the roller press in the related art;

[0024] Figure 5 This is a schematic diagram of the equipment arrangement of a rolling process according to an embodiment of the present application;

[0025] Figure 6 is a schematic diagram of collection points of a sampling cycle of a thickness gauge according to an embodiment of the present application;

[0026] Figure 7 is a schematic diagram of the positions of a roller press and a hydraulic cylinder according to an embodiment of the present application;

[0027] Figure 8 is a schematic diagram of second thickness calculation according to an embodiment of the present application;

[0028] Fig. 9 It is a schematic diagram of the overall structure of a rolling control system for a battery pole piece according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] Some embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0030] In the description of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, it can be indirectly connected through an intermediate medium, it can also be the internal communication of two elements, it can be a wireless connection, or it can be a wired connection.

[0031] In addition, "module" and "processor" may include hardware, software or a combination of the two. A module may include hardware circuits, various suitable sensors, communication ports, and memories, and may also include software parts, such as program codes, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing functions. The processor may be implemented in software, hardware, or a combination of the two. Computer-readable storage media include any suitable media that can store program codes, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc.

[0032] In addition, if the meaning of "and / or" appears in this application, it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "one" and "this" can also include plural forms.

[0033] The battery pole piece coating process refers to coating a layer of material on the substrate so that the positive and negative electrode materials of the battery can be better dispersed and adsorbed, thereby improving the utilization rate of the electrode material and the energy density of the battery. After the coating process, the battery pole piece may have surface density fluctuations, which makes the pole piece thickness inconsistent, and then affects the consistency of the pole piece thickness in the subsequent rolling process. At present, most roller presses use two modes, constant pressure or constant roller gap, to control the thickness of the pole piece, and a thickness gauge is usually placed behind the roller press to perform closed-loop control on it. Due to the hysteresis of closed-loop control, it is impossible to detect the problem of uneven thickness of the incoming material, that is, the battery pole piece, in advance, and it is impossible to ensure the consistency of the pole piece thickness between the thickness gauge and the roller. The uneven thickness of the battery pole piece after rolling will further affect the alignment of the pole ear in the subsequent winding process. In summary, the traditional single-post thickness gauge thickness closed-loop system has certain disadvantages. In order to ensure the consistency of the pole piece rolling process, improve the overall control accuracy of the pole piece, and ensure the uniformity of the rolling thickness, the present application provides a rolling control method for the battery pole piece.

[0034] It should be noted that rolling is a very important process in the manufacturing process of lithium batteries. The rolling control method in the embodiment of the present application is mainly used for the battery pole pieces of lithium batteries, wherein lithium batteries include lithium metal batteries, lithium ion batteries, ternary lithium batteries, etc. The material of the battery pole piece can be lithium iron phosphate, ternary materials, graphite, lithium titanate, etc. It is understandable that this method can also be used to control the rolling operation of the battery pole piece for other batteries that include a rolling process, and the embodiment of the present application does not impose specific restrictions on this. See the attached Figure 1 , Figure 1 FIG. 1 is a flow chart of the main steps of a method for controlling the rolling of a battery electrode sheet according to an embodiment of the present application. Figure 1 As shown, the rolling control method of the battery pole piece mainly includes the following steps S2 to S8.

[0035] Step S2, obtaining a first thickness of the battery electrode sheet before rolling and a second thickness of the battery electrode sheet after rolling.

[0036] The battery pole sheet rolling process usually fixes the coated battery pole sheet to the unwinding mechanism, passes through the gap between the two rollers, and then connects to the winding system. After the rolling begins, the winding mechanism pulls the battery pole sheet steadily through the rolling area, thereby achieving the rolling operation of the battery pole sheet. In this embodiment, it is first necessary to obtain the first thickness of the battery pole sheet before rolling and the second thickness after rolling.

[0037] In one embodiment, a thickness gauge may be placed before and after a rolling device such as a rolling machine to measure a first thickness of the battery electrode sheet before rolling and a second thickness of the battery electrode sheet after rolling.

[0038] In one embodiment, the first thickness and the second thickness are collected and updated in real time, so as to realize the control of the entire rolling process of the battery electrode sheet.

[0039] Step S4, determining current rolling parameters using a closed-loop control algorithm based on the second thickness.

[0040] In this embodiment, the thickness of the controlled object, i.e., the battery electrode sheet after rolling, is used as the feedback quantity, and the expected thickness after rolling is used as the input quantity. The feedback quantity is subtracted from the input quantity to obtain the corresponding error value (deviation), and then the corresponding control quantity, i.e., the current rolling parameter, is calculated based on the error value using PID control, fuzzy control or other methods.

[0041] Step S6: compensating and adjusting the current rolling parameters based on the first thickness.

[0042] This embodiment compensates and adjusts the current rolling parameters based on the first thickness of the battery pole sheet before rolling, thereby solving the impact of inconsistent battery pole sheet thickness on rolling. Specifically, the control amount (rolling parameter) to be compensated is calculated based on the first thickness and the expected thickness before rolling, and the control amount to be compensated is superimposed on the rolling parameter calculated by the closed-loop control algorithm to achieve the purpose of compensation adjustment.

[0043] Step S8, controlling the rolling operation of the battery electrode sheet according to the compensated and adjusted rolling parameters.

[0044] In this embodiment, the compensated and adjusted rolling parameters are used to control the rolling operation of a rolling device such as a rolling machine on a battery electrode sheet.

[0045] This embodiment uses a closed-loop control algorithm to determine the current rolling parameters based on the second thickness of the battery pole piece after rolling, and compensates and adjusts the current rolling parameters based on the first thickness of the battery pole piece before rolling. Finally, the rolling operation of the battery pole piece is controlled according to the compensated and adjusted rolling parameters, thereby achieving the purpose of improving the consistency of the rolled thickness of the battery pole piece, which is beneficial to improving the yield of the battery pole piece manufacturing process, reducing scrap, and ultimately improving the overall yield of the battery.

[0046] In one implementation of the embodiment of the present application, step S4 may further include the following steps S42 and S44:

[0047] Step S42, obtaining a preset second target value of the battery electrode after rolling.

[0048] In this embodiment, the second target value is a preset desired thickness after rolling.

[0049] Step S44, using a closed-loop control algorithm to calculate the current rolling parameters according to the difference between the second thickness and the second target value.

[0050] In this embodiment, the deviation between the second thickness and the second target value is calculated, and then the current rolling parameters are calculated according to the deviation by using methods such as PID control and fuzzy control.

[0051] In one implementation of the embodiment of the present application, step S6 may further include the following steps S62 to S66:

[0052] Step S62, obtaining a preset first target value of the battery electrode sheet before rolling and a thickness compensation function, wherein the thickness compensation function is a correspondence between a change in the thickness of the battery electrode sheet and a change in the rolling parameter obtained through analysis.

[0053] In this embodiment, the first target value is the expected thickness before rolling, and the thickness compensation function is the basic relationship between the thickness and rolling parameters (such as rolling pressure and rolling gap position) established according to different battery electrode materials. As an example, the thickness compensation function can be established by changing the thickness of the battery electrode through multiple experiments and analyzing the relationship between the change in rolling parameters and the change in the thickness of the battery electrode.

[0054] Step S64: determining the rolling parameter variation corresponding to the difference between the first thickness and the first target value according to the thickness compensation function.

[0055] In this embodiment, the deviation between the first thickness and the first target value is calculated, and the deviation is input into the thickness compensation function established in step S62 to obtain the corresponding rolling parameter variation.

[0056] Step S66: taking the sum of the rolling parameter change and the current rolling parameter as the compensated and adjusted rolling parameter.

[0057] In this embodiment, the sum of the rolling pressure parameter change calculated in step S64 and the current rolling pressure parameter calculated in step S4 is used as the rolling pressure parameter after compensation adjustment.

[0058] This embodiment uses a closed-loop control algorithm to calculate the current rolling parameters according to the difference between the second thickness and the second target value, and determines the rolling parameter change corresponding to the difference between the first thickness and the first target value according to the thickness compensation function. The rolling parameter change is used to compensate for the current rolling parameters, which effectively reduces the number of adjustments and adjustment time for rolling the battery pole pieces, improves the automation capability of the rolling process, and solves the problem of uneven pole piece thickness caused by changes in the thickness of the incoming material.

[0059] In one implementation of the embodiment of the present application, step S8 may further include the following step S82:

[0060] Step S82, when the collection position of the first thickness on the battery electrode sheet reaches the rolling area, the rolling operation of the battery electrode sheet is controlled based on the compensated and adjusted rolling parameters.

[0061] In this embodiment, since the transmission mechanism drives the battery pole piece to move, it takes a while for the first thickness collection position of the battery pole piece to reach the rolling area such as the rolling gap position area before rolling. In this embodiment, the first thickness collection position is monitored by a position sensor and other devices. When it reaches the rolling area, the rolling parameter change is used to compensate and adjust the current rolling parameter. This achieves accurate correction of the battery pole piece thickness change and further improves the consistency of the pole piece rolling thickness.

[0062] In an optional embodiment, without using a closed-loop control algorithm to calculate the current rolling parameters, the difference between the first thickness and the second target value can be used as the input of the thickness compensation function to calculate the corresponding rolling parameter change, and the rolling parameter change can be used to control the rolling operation of the battery electrode.

[0063] In an optional embodiment, the first thickness includes the average thickness of multiple sampling points of the battery pole sheet that has not passed through the rolling area within a preset sampling period; the second thickness includes the average thickness of multiple sampling points of the battery pole sheet that has passed through the rolling area within a preset sampling period.

[0064] In this embodiment, the first thickness and the second thickness are calculated using the average thickness of multiple sampling points of the battery electrode within a preset sampling period, thereby achieving the purpose of improving the accuracy of thickness collection and compensation, and achieving the effect of improving the rolling control accuracy and thickness uniformity of the electrode.

[0065] In an optional embodiment, the rolling parameters include a rolling pressure value, and the above-mentioned rolling control method for the battery pole piece further includes the following step S7:

[0066] Step S7: storing the compensated and adjusted pressure value corresponding to the acquisition position of the first thickness on the battery electrode during the rolling process.

[0067] In this embodiment, the compensated pressure value corresponding to the acquisition position of the first thickness is recorded.

[0068] In one implementation, the first thickness is acquired in real time and the compensated and adjusted pressure value corresponding to the first thickness is recorded.

[0069] In an optional implementation, after the above step S7, the following step S9 may be further included:

[0070] Step S9, when the compensated and adjusted rolling parameters are greater than a preset safety threshold, an alarm is issued and the rolling operation of the battery electrode is stopped.

[0071] In this embodiment, when the compensated and adjusted rolling parameters, such as the compensated and adjusted pressure value, are greater than a preset pressure safety threshold, an alarm is issued and the rolling operation on the battery electrode sheet is stopped.

[0072] It should be pointed out that although the various steps in the above embodiments are described in a specific order, those skilled in the art can understand that in order to achieve the effect of the present application, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders. These changes are within the scope of protection of the present application.

[0073] In a second aspect, the present application provides a rolling control system for a battery pole piece, such as Figure 2 As shown, the system includes: a thickness acquisition module 202, which is used to obtain the first thickness of the battery electrode before rolling and the second thickness after rolling; a parameter determination module 204, which determines the current rolling parameters based on the second thickness using a closed-loop control algorithm; a compensation adjustment module 206, which compensates and adjusts the current rolling parameters based on the first thickness; and a rolling control module 208, which is used to control the rolling operation of the battery electrode according to the compensated and adjusted rolling parameters.

[0074] The above-mentioned battery pole sheet rolling control system is used to execute Figure 1 The rolling control method embodiment of the battery pole piece shown in the figure has similar technical principles, technical problems solved and technical effects produced. Technicians in this technical field can clearly understand that for the convenience and conciseness of description, the specific working process and related instructions of the system can refer to the contents described in the above method embodiment, which will not be repeated here.

[0075] In an optional embodiment, the thickness acquisition module includes: a first thickness gauge and a second thickness gauge, wherein the first thickness gauge is used to obtain a first thickness of the battery electrode before being rolled, and the second thickness gauge is used to obtain a second thickness of the battery electrode after being rolled, wherein the distance between the first thickness gauge and the rolling area is equal to the distance between the second thickness gauge and the rolling area.

[0076] In this embodiment, the distance between the first thickness gauge and the rolling area is equal to the distance between the second thickness gauge and the rolling area. This is to facilitate the first thickness collection position to be sampled again by the second thickness gauge after rolling, thereby achieving the purpose of improving the consistency of the rolling thickness and verifying the compensation adjustment results.

[0077] In an example of an application scenario in this application, Figure 3 FIG. 1 is a schematic diagram of a rolling process of a battery electrode according to an embodiment of the present application. Figure 3 As shown, the battery pole piece passes through the first thickness gauge, the roller press (rolling equipment) and the second thickness gauge in sequence during rolling, and the control module is a module used for calculation and control in the rolling control system of the battery pole piece. The first thickness gauge collects the first thickness of the battery pole piece before rolling, and the second thickness gauge collects the second thickness of the battery pole piece after rolling. The control module calculates the first thickness deviation according to the difference between the first thickness and the first target value, and calculates the second thickness deviation according to the difference between the second thickness and the second target value. Among them, the thickness deviation represents the difference between the actual thickness and the target thickness. The control module uses a closed-loop control algorithm based on the second thickness deviation to determine the current rolling parameters, calculates the rolling parameter change according to the thickness compensation function and the first thickness deviation, and then controls the roller press to roll the battery pole piece according to the sum of the rolling parameter change and the current rolling parameter.

[0078] In one embodiment, the first thickness gauge is used to measure the first thickness deviation of the battery electrode before rolling, that is, the difference between the actual thickness before rolling and the target thickness. For example, the target thickness of the battery electrode before rolling is 100um, but the uneven coating makes the actual thickness of some positions on the battery electrode not equal to 100um. Then when the actual thickness of the electrode is equal to 100um, the first thickness deviation is equal to 0, and when the actual thickness is not equal to 100um, the first thickness deviation is equal to the actual thickness collected by the first thickness gauge minus 100. Similarly, the second thickness gauge is used to measure the second thickness deviation of the battery electrode after rolling, that is, the difference between the actual thickness after rolling and the target thickness. For example, if the target thickness after rolling is required to be 60um, then when the actual thickness after rolling is 60um, the second thickness deviation is equal to 0, and when the actual thickness after rolling is not equal to 60um, the second thickness deviation is equal to the actual thickness collected by the first thickness gauge minus 60um. In other words, the first thickness gauge and the second thickness gauge can directly calculate the thickness deviation and send it to the control module.

[0079] Optional, Figure 4 The figure is a schematic diagram of the thickness closed-loop control of the roller press in the related technology. Among them, the roller thickness closed-loop technology is a classic control system solution, which is mainly composed of a controller (such as a computer), a detection element (such as a sensor) and an actuator (such as a hydraulic cylinder). Figure 4As shown, the thickness gauge detects the difference Δh between the actual thickness of the battery electrode and the target thickness, and transmits it to the controller. The controller calculates the control signal based on the thickness difference Δh using a closed-loop control algorithm such as a PID control algorithm, and then sends the control signal to an actuator such as a hydraulic cylinder, which adjusts the roller position through the hydraulic cylinder to adjust the pressure of the battery electrode roll. After that, the thickness gauge feeds back the adjusted rolling thickness to the controller to form a closed-loop control loop. It should be noted that the above control system has a lag in adjusting the roller press, and the thickness cannot be adjusted for the distance from the thickness gauge to the roller, making it difficult to ensure the consistency of the electrode roll thickness.

[0080] In an example of an application scenario of the present application, the battery pole sheet roller pressing control system is used to control Figure 5 The rolling process equipment rolls the battery pole piece. Specifically, the battery pole piece is controlled by the unwinding mechanism and the winding mechanism to be conveyed along the rolling direction. The first thickness gauge and the second thickness gauge are set at equal positions on both sides of the rolling machine, and the first thickness of the battery pole piece before rolling and the second thickness after rolling are respectively obtained and sent to the rolling control system. The rolling control system uses a closed-loop control algorithm based on the second thickness to determine the current rolling parameters, compensates and adjusts the current rolling parameters based on the first thickness, and then sends the compensated rolling parameters to the rolling machine to realize the rolling operation of the battery pole piece.

[0081] In one embodiment, the distance between the first thickness gauge and the rolling area may be unequal to the distance between the second thickness gauge and the rolling area. In this case, the sampling periods of the first thickness gauge and the second thickness gauge may be adjusted respectively according to the distances between the first thickness gauge and the second thickness gauge and the rolling area and the movement speed of the battery electrode, so as to achieve the purpose of collecting the first thickness before rolling and the second thickness after rolling at the same position of the battery electrode.

[0082] In one embodiment, the probe of the thickness gauge (such as a laser thickness gauge) moves back and forth perpendicular to the rolling direction as a sampling cycle. The sampling cycle can be set with the number of measurement points. As an example, assuming a sampling cycle of 1ms and a number of measurement points of 5, since the battery electrode is transmitted along the rolling direction, the thickness gauge has a sampling point of 1ms in a sampling cycle. Figure 6 shown.

[0083] In one embodiment, the first thickness deviation and the second thickness deviation are calculated based on average values ​​of thicknesses at multiple sampling points of the first thickness gauge and the second thickness gauge within a sampling period.

[0084] In one embodiment, the thickness measured by the thickness gauge can be the average value of the thickness of multiple sampling points in a sampling period of the thickness gauge, and accordingly, the first thickness deviation is the difference between the average value and the first target value. The second thickness deviation is similar.

[0085] In one embodiment, the roller pressing device includes a servo valve and a hydraulic cylinder in addition to the roller press, and the servo valve and the hydraulic cylinder can be used to adjust the pressure of the roller press. The roller pressing control system can adjust the roller gap and pressure of the roller press by controlling the servo valve and the hydraulic cylinder. For example, the flow of the hydraulic cylinder can be adjusted by adjusting the opening of the servo valve, the roller gap of the roller press can be adjusted by the flow of the hydraulic cylinder, and the roller pressure of the roller press can be adjusted by the roller gap of the roller press.

[0086] In one embodiment, when the rolling control system controls the servo valve, the rolling parameter can also be an electrical signal, such as controlling the opening of the servo valve through a current signal, thereby driving the movement of the hydraulic cylinder, changing the position of the roller (roll gap) of the rolling machine, and ultimately achieving the adjustment of the rolling pressure.

[0087] In an optional embodiment, if Figure 7 As shown, the upper roller of the roller press is fixed, and two hydraulic cylinders are provided at the bottom of the lower roller perpendicular to the rolling direction, and the battery pole piece is rolled through the roller gap. The control module can also monitor the pressure difference between hydraulic cylinder 1 and hydraulic cylinder 2, and alarm and stop the machine when the pressure difference exceeds the preset safety threshold.

[0088] In one embodiment, the rolling control system controls the two hydraulic cylinders respectively, so the battery pole piece is divided into two equal parts corresponding to the two hydraulic cylinders. The first thickness gauge and the second thickness gauge respectively collect the first thickness before rolling and the second thickness after rolling of any part, and the rolling control system calculates the current rolling parameters and compensates and adjusts them, thereby realizing the control of the hydraulic cylinders on either side.

[0089] In one embodiment, if Figure 8 As shown, a to i are multiple sampling points of the second thickness gauge in a sampling cycle. After the battery pole piece and the two hydraulic cylinders are divided into two parts correspondingly, hydraulic cylinder 1 and hydraulic cylinder 2 use sampling points a, b, h, i and sampling points c, d, e, f, g to calculate the second thickness respectively. The calculation method of the first thickness is similar to that of the second thickness gauge, thereby achieving the purpose of adjusting hydraulic cylinder 1 and hydraulic cylinder 2 respectively. The specific method can be found in the contents of other embodiments of the present application, which will not be repeated here.

[0090] In one embodiment, the roller pressure control system can also record the pressure and displacement of the hydraulic cylinder.

[0091] In this embodiment, by feeding back the displacement and pressure parameters of the hydraulic cylinder to the control module, the controlled output is fed back to the control input terminal to form a feedback control loop.

[0092] In an optional embodiment, Fig. 9 Schematic diagram of the overall structure of a rolling control system for a battery pole piece according to an embodiment of the present application. Fig. 9 As shown, the first thickness gauge obtains the first thickness of the incoming material, calculates the first thickness deviation, and sends the first thickness deviation to the control module. Similarly, the second thickness gauge obtains the second thickness of the battery electrode after being rolled by the roller press, calculates the second thickness deviation, and sends the second thickness deviation to the control module. The control module calculates the compensated and adjusted rolling parameters based on the first thickness deviation and the second thickness deviation, and controls the electro-hydraulic servo valve, hydraulic cylinder, and roller gap based on the parameters to adjust the roller press pressure, and finally controls the roller press to roll the battery electrode.

[0093] It should be noted that each hydraulic cylinder has a magnetic ruler at the center, which is used as a relative displacement sensor to detect the displacement of the upper cylinder piston. Each hydraulic cylinder also includes a pressure sensor to detect the rolling pressure on both sides of the hydraulic cylinder. The detected displacement and pressure signals can be fed back to the control module to form a closed-loop control circuit, and finally realize the intelligent calibration of the roll gap position of the roller press.

[0094] This embodiment can effectively solve the effect of uneven coating surface density on rolling thickness of battery pole pieces, and realizes the purpose of automatically adjusting rolling parameters based on thickness. There is no need to stop the roller press to adjust the roller gap during operation, thereby achieving the effect of improving the consistency of pole piece thickness and reducing equipment downtime. This embodiment can achieve one-time adjustment during the rolling process, effectively shortening the adjustment time. While improving the consistency of battery pole piece thickness, it also improves the alignment of the pole ears in the subsequent winding process, thereby achieving the effect of reducing the pole piece scrap rate and improving the product quality rate.

[0095] It can be understood that the technical principles, technical problems solved and technical effects produced by the above-mentioned battery pole sheet rolling control system and the battery pole sheet rolling control method in other embodiments of the present application are similar. Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working process and related instructions of the battery pole sheet rolling control system can refer to the contents described in the embodiment of the battery pole sheet rolling control method, which will not be repeated here.

[0096] It is understood by those skilled in the art that all or part of the processes in the method for implementing the above-mentioned embodiment of the present application can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable storage medium may include: any entity or device, medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal and software distribution medium, etc. that can carry the computer program code.

[0097] In a third aspect, the present application also provides a computer-readable storage medium.

[0098] In an embodiment of a computer-readable storage medium according to the present application, the computer-readable storage medium may be configured to store a program for executing the rolling control method of the battery pole piece of the above-mentioned method embodiment, and the program may be loaded and run by the processor to implement the rolling control method of the battery pole piece. For ease of explanation, only the parts related to the embodiment of the present application are shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present application. The computer-readable storage medium may be a storage device formed by various electronic devices. Optionally, the computer-readable storage medium in the embodiment of the present application is a non-temporary computer-readable storage medium.

[0099] So far, the technical solution of the present application has been described in conjunction with an embodiment shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. A rolling control method for a battery pole piece, characterized in that: include: Obtaining a first thickness of the battery electrode sheet before rolling and a second thickness of the battery electrode sheet after rolling; Determine current rolling parameters using a closed-loop control algorithm based on the second thickness; Performing compensation adjustment on the current rolling parameters based on the first thickness; The rolling operation of the battery pole piece is controlled according to the rolling parameters after compensation adjustment.

2. The method according to claim 1, characterized in that The method of determining the current rolling parameters by using a closed-loop control algorithm based on the second thickness includes: Obtaining a preset second target value of the battery electrode after rolling; The current rolling parameter is calculated according to the difference between the second thickness and the second target value by using a closed-loop control algorithm.

3. The method according to claim 1, characterized in that The compensating and adjusting the current rolling parameters based on the first thickness includes: Obtaining a preset first target value of the battery pole piece before rolling and a thickness compensation function, wherein the thickness compensation function is a corresponding relationship between a change in the thickness of the battery pole piece and a change in a rolling parameter obtained through analysis; determining, according to the thickness compensation function, a rolling parameter change amount corresponding to a difference between the first thickness and the first target value; The sum of the rolling parameter change and the current rolling parameter is used as the rolling parameter after compensation adjustment.

4. The method according to any one of claims 1 to 3, characterized in that The step of controlling the rolling operation of the battery pole piece according to the compensated and adjusted rolling parameters includes: When the collection position of the first thickness on the battery electrode sheet reaches the rolling area, the rolling operation of the battery electrode sheet is controlled based on the compensated and adjusted rolling parameters.

5. The method according to claim 4, characterized in that The first thickness includes an average value of thicknesses of a plurality of sampling points of a battery electrode sheet that has not passed through the rolling area within a preset sampling period; The second thickness includes an average value of thicknesses of a battery electrode sheet passing through the rolling area at multiple sampling points within a preset sampling period.

6. The method according to claim 1, characterized in that The rolling parameters include a rolling pressure value, and the method further includes: The compensated and adjusted pressure value corresponding to the acquisition position of the first thickness on the battery electrode during the rolling process is stored.

7. The method according to claim 1, characterized in that The method further comprises: When the compensated and adjusted rolling parameter is greater than a preset safety threshold, an alarm is triggered and the rolling operation on the battery electrode is stopped.

8. A rolling control system for a battery pole piece, characterized in that: include: A thickness acquisition module, used to acquire a first thickness of the battery electrode sheet before rolling and a second thickness of the battery electrode sheet after rolling; a parameter determination module, which determines current rolling parameters using a closed-loop control algorithm based on the second thickness; a compensation adjustment module, for compensating and adjusting the current rolling parameters based on the first thickness; The rolling control module is used to control the rolling operation of the battery pole piece according to the rolling parameters adjusted after compensation.

9. The system according to claim 8, characterized in that The thickness acquisition module comprises: A first thickness gauge and a second thickness gauge, wherein the first thickness gauge is used to obtain a first thickness of the battery electrode sheet before rolling, and the second thickness gauge is used to obtain a second thickness of the battery electrode sheet after rolling, wherein the distance between the first thickness gauge and the rolling area is equal to the distance between the second thickness gauge and the rolling area.

10. A computer-readable storage medium storing a plurality of program codes, characterized in that: The program code is suitable for being loaded and executed by a processor to execute the method according to any one of claims 1 to 7.

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