Control method, device and system for thickness of battery electrode sheet, and storage medium

Abstract

A control method, device and system for the thickness of a battery electrode sheet, and a storage medium. The control method comprises: constructing a formula model in which a target thickness of an electrode sheet to be calendered changes along with an initial thickness and an actual calendering force, wherein the actual calendering force is related to output pressure from a main pressure source and a pressing force borne by a limiting member (S301); and on the basis of the pressing force borne by the limiting member during the calendering of said electrode sheet and the formula model, adjusting the output pressure from the main pressure source, so as to calender said electrode sheet from the initial thickness to the target thickness (S302). Thus, by means of firstly constructing a formula model before executing a calendering operation, and adjusting output pressure from a main pressure source on the basis of the formula model and a pressing force borne by a limiting member, so as to calender an electrode sheet to be calendered, the output pressure from the main pressure source can be quickly and accurately adjusted, thereby improving the thickness consistency of said electrode sheet after being calendered, reducing the misalignment proportion of tabs after winding electrode sheets, and improving the thickness consistency of cells.

Description

A battery electrode thickness control method, device, system and storage medium

[0001] This application claims priority to Chinese patent application No. 2024103539807, filed on March 26, 2024, entitled “A method, device, system and storage medium for controlling the thickness of a battery electrode”, which is incorporated herein by reference in its entirety.

Technical field

[0002] The present application relates to the field of battery technology, and in particular to a method, device, system and storage medium for controlling the thickness of a battery electrode. [Background Technology]

[0003] Energy conservation and emission reduction are key to sustainable development, which in turn promotes the adjustment of energy structure and drives the development and application of battery technology. The key to the development of battery technology lies in electrochemical energy storage technology. Due to its advantages such as high energy density, good cycle life, high operating voltage, environmental friendliness, and low self-discharge, it has been widely used in portable electronics, electric vehicles, and energy storage systems.

[0004] The production process of lithium battery pole pieces involves the process of rolling the pole pieces. Currently, with the rapid development of lithium battery technology, higher and higher requirements are placed on the thickness uniformity of battery pole pieces. The thickness consistency of the pole pieces has an important impact on the subsequent winding tab misalignment and battery cell thickness consistency. The traditional rolling process generally requires employees to manually adjust the rolling pressure to control the thickness of the pole pieces out of the roller, which is prone to problems such as poor thickness consistency of the produced electrode pole pieces.

[0005] [Summary of the invention]

[0006] In order to solve the above-mentioned technical problems existing in the prior art, the present application provides a battery electrode thickness control method, device, system and storage medium.

[0007] To solve the above problems, the present application provides a method for controlling the thickness of a battery pole piece, the control method comprising: constructing a formula model for how the target thickness of the pole piece to be rolled changes with the initial thickness and the actual rolling force, wherein the actual rolling force is related to the output pressure of the main pressure source and the extrusion force exerted on the limiter; based on the extrusion force exerted on the limiter during the rolling of the pole piece to be rolled and the formula model, adjusting the output pressure of the main pressure source to roll the pole piece to be rolled from the initial thickness to the target thickness. Thus, before performing the rolling operation, the formula model is first constructed, and then the output pressure of the main pressure source is adjusted according to the formula model and the extrusion force exerted on the limiter to roll the pole piece to be rolled, so that the output pressure of the main pressure source can be adjusted quickly and accurately, thereby improving the consistency of the thickness of the rolled pole piece to be rolled, reducing the proportion of tab misalignment after winding the pole piece, and improving the consistency of the thickness of the battery cell.

[0008] In some embodiments, the step of adjusting the output pressure of the main pressure source based on the extrusion force applied to the limiter during the rolling of the pole piece to be rolled and the formula model includes: obtaining the extrusion force applied to the limiter at a preset frequency during the rolling of the pole piece to be rolled, thereby obtaining a plurality of extrusion forces; and in response to the force difference between two extrusion forces of adjacent frequencies among the plurality of extrusion forces being greater than a preset force difference threshold, adjusting the output pressure of the main pressure source based on the force difference and the formula model. Thus, when the difference between two extrusion forces of adjacent frequencies is greater than the preset force difference threshold, adjusting the output pressure of the main pressure source based on the force difference and the formula model can more accurately adjust the output pressure of the main pressure source and improve the consistency of the thickness of the rolled pole piece to be rolled.

[0009] In some embodiments, the step of adjusting the output pressure of the main pressure source based on the force difference and the formula model includes: determining a thickness fluctuation value corresponding to the force difference based on the formula model and the force difference; and adjusting the output pressure of the main pressure source in response to the thickness fluctuation value being greater than a preset thickness threshold. Thus, by determining the thickness fluctuation value based on the force model and the force difference, and adjusting the output pressure of the main pressure source when the thickness fluctuation value is greater than the preset thickness threshold, the output pressure of the main pressure source can be adjusted more accurately, thereby improving the consistency of the thickness of the rolled pole piece.

[0010] In some embodiments, after the step of adjusting the output pressure of the main pressure source based on the extrusion force applied to the stopper during the rolling process of the to-be-rolled pole piece and the formula model, the control method further includes: detecting the actual thickness of the rolled to-be-rolled pole piece; and correcting the formula model in response to the difference between the actual thickness and the target thickness being greater than a preset thickness difference threshold. Thus, after the rolling of the to-be-rolled pole piece is completed, the actual thickness of the to-be-rolled pole piece can be detected. If the difference between the actual thickness and the target thickness is large, the formula model can be corrected. This facilitates using the corrected formula model to adjust the output pressure of the main pressure source, thereby improving the consistency of the thickness of the rolled to-be-rolled pole piece.

[0011] In some embodiments, the step of constructing a formula model for how the target thickness of a to-be-rolled pole piece varies with its initial thickness and actual rolling force includes: obtaining the target thickness, the initial thickness, and the tape speed at which the pole piece is rolled; and generating the formula model based on a deformation coefficient generated from the target thickness, the initial thickness, the actual rolling force, and the tape speed. Thus, by simultaneously considering the target thickness, initial thickness, actual rolling force, and tape speed to generate the formula model, the formula model can be used to precisely control the output pressure of the main pressure source, thereby improving the consistency of the thickness of the rolled pole piece.

[0012] In some embodiments, the target thickness in the formula model is equal to the difference between the initial thickness and the product of the deformation coefficient and the actual rolling force. Thus, by forming a simple calculation formula model using the target thickness, the initial thickness, the deformation coefficient, and the actual rolling force, it is convenient to quickly determine the output pressure of the main pressure source that needs to be adjusted, thereby improving the consistency of the thickness of the rolled pole piece.

[0013] In some embodiments, the actual rolling force is equal to the difference between a first pressure value and a second pressure value, wherein the first pressure value is equal to the product of a first coefficient and the output pressure of the main pressure source, and the second pressure value is equal to the product of the second coefficient and the extrusion force. This allows for more accurate determination of the actual rolling force, facilitates rapid determination of the output pressure of the main pressure source that requires adjustment, and improves the consistency of the thickness of the rolled pole piece.

[0014] In some embodiments, the actual rolling force is equal to the difference between the first pressure value and the second pressure value, the third pressure value, and the gravity of the lower rolling portion, wherein the third pressure value is equal to the product of the third coefficient and the force applied by the auxiliary pressure source. Thus, by simultaneously considering the effects of the gravity of the lower rolling portion and the force applied by the auxiliary pressure source on the actual rolling force, the actual rolling force can be made closer to reality, thereby facilitating more accurate determination of the output pressure of the main pressure source that needs to be adjusted, thereby improving the consistency of the thickness of the rolled pole piece to be rolled.

[0015] To solve the above problems, the present application provides a battery electrode thickness control device, which includes a processor and a memory, wherein a computer program is stored in the memory, and the processor is used to execute the computer program to implement the above-mentioned battery electrode thickness control method.

[0016] In order to solve the above problems, the present application provides a computer-readable storage medium having program instructions stored thereon, and the program instructions, when executed by a processor, implement the above-mentioned battery electrode thickness control method.

[0017] To solve the above problems, the present application provides a battery pole sheet thickness control system, which includes a controller and a rolling device. The controller is used to execute the above battery pole sheet thickness control method to control the rolling device to roll the pole sheet to be rolled.

[0018] In some embodiments, the rolling device includes an upper rolling part, a lower rolling part, a main pressure source, and a limiter. The limiter is supported between the upper rolling part and the lower rolling part. The main pressure source is used to output pressure to the upper rolling part and / or the lower rolling part to roll the pole piece to be rolled passing between the upper rolling part and the lower rolling part. Therefore, the limiter is located between the upper rolling part and the lower rolling part. When the main pressure source outputs pressure to the upper rolling part and / or the lower rolling part, the limiter can more quickly reflect the extrusion force received, thereby realizing a low-cost and high-precision control solution for the output pressure of the main pressure source.

[0019] In some embodiments, the rolling device further comprises an auxiliary pressure source, which is located between the upper rolling part and the lower rolling part and is closer to the ends of the upper rolling part and the lower rolling part than the stopper. Thus, the auxiliary pressure source is located between the upper rolling part and the lower rolling part and is closer to the ends of the upper rolling part and the lower rolling part than the stopper. The auxiliary pressure source can alleviate the disturbance deformation of the upper and lower rolling parts during the rolling process, thereby improving the service life of the rolling device.

[0020] In some embodiments, the limiting member includes a first limiting portion and a second limiting portion, the first limiting portion and the second limiting portion abutting against each other in the direction of the spacing between the upper and lower rolling portions, and at least one of the first limiting portion and the second limiting portion includes a pressure sensor. Thus, the limiting member includes the first limiting portion and the second limiting portion, and at least one of the first limiting portion and the second limiting portion includes a pressure sensor. The pressure sensor can quickly and accurately detect the extrusion force applied to the limiting member, thereby more accurately determining the output pressure of the main pressure source that needs to be adjusted.

[0021] In some embodiments, the control system further comprises a thickness detector, which is located downstream of the rolling device in the direction of travel of the pole piece to be rolled. Thus, the thickness detector is provided downstream of the rolling device to facilitate detection of the actual thickness of the rolled pole piece to be rolled.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

Brief Description of the Drawings

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] FIG1 is a schematic structural diagram of a battery electrode thickness control system according to one or more embodiments of the present application;

[0025] FIG2 is a cross-sectional view of a rolling device according to one or more embodiments of the present application;

[0026] FIG3 is a flow chart of a method for controlling the thickness of a battery electrode sheet according to one or more embodiments of the present application;

[0027] FIG4 is a schematic flow chart of an embodiment of step S301 in FIG3 ;

[0028] FIG5 is a schematic block diagram of a battery electrode thickness control device according to one or more embodiments of the present application;

[0029] FIG6 is a schematic block diagram of the structure of a computer storage medium according to one or more embodiments of the present application. [Specific implementation method]

[0030] The present application will be further described in detail below in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only intended to illustrate the present application and are not intended to limit the scope of the present application. Similarly, the following examples are only some examples of the present application and not all examples. All other examples obtained by those of ordinary skill in the art without creative work are intended to fall within the scope of protection of this application.

[0031] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can mean fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or connection through an intermediate medium. Those skilled in the art will be able to understand the specific meanings of the above terms in this application in specific circumstances.

[0033] Energy conservation and emission reduction are key to sustainable development, which in turn promotes the adjustment of energy structure and drives the development and application of battery technology. The key to the development of battery technology lies in electrochemical energy storage technology. Due to its advantages such as high energy density, good cycle life, high operating voltage, environmental friendliness, and low self-discharge, it has been widely used in portable electronics, electric vehicles, and energy storage systems.

[0034] The production process of lithium battery pole pieces involves the process of rolling the pole pieces. Currently, with the rapid development of lithium battery technology, higher and higher requirements are placed on the thickness uniformity of battery pole pieces. The thickness consistency of the pole pieces has an important impact on the subsequent winding tab misalignment and battery cell thickness consistency. The traditional rolling process generally requires employees to manually adjust the rolling pressure to control the thickness of the pole pieces out of the roller, which is prone to problems such as poor thickness consistency of the produced electrode pole pieces.

[0035] In order to solve the technical problems existing in the related art, the present application provides a battery pole piece thickness control method, equipment, system and storage medium, wherein a slurry is coated on the current collector of the pole piece, and the slurry is dried to form a pole piece to be rolled, and the pole piece to be rolled is rolled by a rolling device, and the rolling device may include an upper rolling part, a lower rolling part, a limiter and a main pressure source, the limiter is clamped between the upper rolling part and the lower rolling part, and the main pressure source is used to output pressure. In order to make the thickness of the pole piece at different positions after rolling as consistent as possible, a formula model can be constructed to show that the target thickness of the pole piece to be rolled changes with the initial thickness and the actual rolling force, the extrusion force exerted on the limiter is detected, and the output pressure of the main pressure source is adjusted in combination with the formula model to roll the pole piece to be rolled from the initial thickness to the target thickness, thereby improving the consistency of the thickness of the rolled pole piece to be rolled.

[0036] Specifically, the present application provides a battery pole sheet thickness control system. For details, see Figures 1 and 2. Figure 1 is a schematic structural diagram of a battery pole sheet thickness control system according to one or more embodiments of the present application. Figure 2 is a cross-sectional view of a rolling device according to one or more embodiments of the present application.

[0037] The battery electrode thickness control system 10 includes a controller 300 and a rolling device 100. The controller 300 can be used to execute the battery electrode thickness control method of any of the following embodiments to control the rolling device 100 to roll the electrode sheet 200 to be rolled. The electrode sheet 200 to be rolled can include a current collector and a slurry coated on the current collector. The slurry is dried to form the electrode sheet 200 to be rolled. The current collector can be a positive electrode current collector or a negative electrode current collector, and the corresponding slurry is a positive electrode active material or a negative electrode active material. The rolling device 100 can be used to roll the electrode sheet 200 to be rolled to roll the electrode sheet 200 to be rolled from the initial thickness to the target thickness. The controller 300 can control the rolling device 100 to output a specific pressure so that the rolling device 100 rolls the electrode sheet 200 to be rolled according to the specific pressure. Specifically, the rolling equipment 100 may include a main pressure source 130 and a limiter 140, and the controller 300 can be used to construct a formula model in which the target thickness of the pole piece 200 to be rolled changes with the initial thickness and the actual rolling force, wherein the actual rolling force is related to the output pressure of the main pressure source 130 and the extrusion force exerted on the limiter 140; based on the extrusion force exerted on the limiter 140 during the rolling process of the pole piece 200 to be rolled and the formula model, the output pressure of the main pressure source 130 is adjusted to roll the pole piece 200 to be rolled from the initial thickness to the target thickness.

[0038] Through the above-mentioned embodiment, before performing the rolling operation, a formula model is first constructed, and then the output pressure of the main pressure source 130 is adjusted according to the formula model and the extrusion force exerted on the limiter 140 to roll the pole piece 200 to be rolled. In this way, the output pressure of the main pressure source 130 can be adjusted quickly and accurately, thereby improving the consistency of the thickness of the rolled pole piece 200 to be rolled, reducing the proportion of pole ear misalignment after winding the pole piece, and improving the consistency of the battery cell thickness.

[0039] Furthermore, the rolling equipment 100 includes an upper rolling part 120, a lower rolling part 110, a main pressure source 130 and a limiter 140, the limiter 140 is supported between the upper rolling part 120 and the lower rolling part 110, and the main pressure source 130 is used to output pressure to the upper rolling part 120 and / or the lower rolling part 110 to roll the pole piece 200 to be rolled passing between the upper rolling part 120 and the lower rolling part 110. Both the upper rolling part 120 and the lower rolling part 110 can be rollers. The rollers can be divided into three parts along their length. The radial dimensions of the two end parts are smaller than the radial dimensions of the middle part. The middle part of the upper rolling part 120 corresponds to the middle part of the lower rolling part 110. The pole piece 200 to be rolled passes through the middle part of the upper rolling part 120 and the middle part of the lower rolling part 110, and is rolled by the middle part of the upper rolling part 120 and the middle part of the lower rolling part 110. The limiter 140 can be supported between the parts at the two ends of the upper rolling part 120 and the lower rolling part 110 to limit the distance between the upper rolling part 120 and the lower rolling part 110. There can be two limiters 140, and one limiter 140 can be provided between each corresponding end of the upper rolling part 120 and the lower rolling part 110. The main pressure source 130 can include, but is not limited to, a hydraulic cylinder, etc. The main pressure source 130 can be installed on the upper rolling part 120, or on the lower rolling part 110, or on both the upper rolling part 120 and the lower rolling part 110. For example, taking Figure 2 as an example, the main pressure source 130 is installed at the end of the lower rolling part 110. There can be two main pressure sources 130, one of which is installed at each end of the lower rolling part 110. The main pressure sources 130 apply pressure to the lower rolling part 110 to cooperate with the upper rolling part 120 to roll the pole piece 200 to be rolled. Therefore, the limiter 140 is located between the upper rolling part 120 and the lower rolling part 110. When the main pressure source 130 outputs pressure to the upper rolling part 120 and / or the lower rolling part 110, the limiter 140 can more quickly reflect the extrusion force received, thereby realizing a low-cost and high-precision control solution for the output pressure of the main pressure source 130.

[0040] Furthermore, the rolling equipment 100 also includes an auxiliary pressure source 150, which is located between the upper rolling part 120 and the lower rolling part 110, and is closer to the ends of the upper rolling part 120 and the lower rolling part 110 than the limiter 140. The auxiliary pressure source 150 may include, but is not limited to, a hydraulic cylinder, etc. The auxiliary pressure source 150 may be located between the parts at both ends of the upper rolling part 120 and the lower rolling part 110. There may be two auxiliary pressure sources 150, and an auxiliary pressure source 150 may be provided between each corresponding end of the upper rolling part 120 and the lower rolling part 110. The auxiliary pressure source 150 is closer to the ends of the upper rolling part 120 and the lower rolling part 110, and the auxiliary pressure source 150 can alleviate the disturbance deformation generated by the upper rolling part 120 and the lower rolling part 110 during the rolling process, thereby improving the service life of the rolling equipment 100.

[0041] In some embodiments, the stopper 140 includes a first stopper 141 and a second stopper 142, which abut against each other in the direction separating the upper crushing portion 120 and the lower crushing portion 110. At least one of the first stopper 141 and the second stopper 142 includes a pressure sensor. Both the first stopper 141 and the second stopper 142 may be inclined irons, with the inclined surfaces of the first stopper 141 and the second stopper 142 abutting against each other. At least one of the first stopper 141 and the second stopper 142 may be a pressure sensor. For example, the first stopper 141 may be replaced with a structure comprising multiple arranged pressure sensors; or a groove may be provided in the first stopper 141 or the second stopper 142, and a pressure sensor may be embedded in the groove; or a strain gauge may be interposed between the first stopper 141 and the second stopper 142, so that the pressure sensor can detect and calculate the actual force applied to the stopper 140. Therefore, the limit member 140 includes a first limit part 141 and a second limit part 142, and at least one of the first limit part 141 and the second limit part 142 includes a pressure sensor, which can quickly and accurately detect the extrusion force applied to the limit member 140 through the pressure sensor, thereby more accurately determining the output pressure of the main pressure source 130 that needs to be adjusted.

[0042] In some embodiments, the control system 10 further includes a thickness detector 400, which is located downstream of the rolling equipment 100 in the running direction of the pole piece 200 to be rolled. The running direction of the pole piece 200 to be rolled can be understood as the direction in which the pole piece 200 to be rolled gradually enters the rolling equipment 100 from outside the rolling equipment 100 to be rolled by the rolling equipment 100. The thickness detector 400 may include, but is not limited to, a laser thickness detector 400. The thickness detector 400 is located downstream of the rolling equipment 100 in the running direction, and can facilitate detection of the actual thickness of the rolled pole piece 200 to be rolled by the thickness detector 400.

[0043] To address the technical issues in the related art, this application provides a method for controlling the thickness of a battery electrode sheet. This method can be executed by the controller in the above-described embodiments. Referring to Figure 3 , Figure 3 is a schematic flow chart of a method for controlling the thickness of a battery electrode sheet according to one or more embodiments of this application. Specifically, the method includes the following steps S301 to S302 .

[0044] Step S301: constructing a formula model for how the target thickness of the electrode to be rolled changes with the initial thickness and the actual rolling force, wherein the actual rolling force is related to the output pressure of the main pressure source and the extrusion force exerted on the limiter.

[0045] The target thickness can be understood as the thickness of the pole piece to be rolled after rolling. The initial thickness can be understood as the thickness of the pole piece to be rolled before rolling. The actual rolling force can be understood as the rolling force to which the pole piece to be rolled is subjected during the rolling process. The pole piece to be rolled can be rolled by a rolling device according to any of the above embodiments. For example, the rolling device includes an upper rolling part, a lower rolling part, a main pressure source and a limiter. The limiter is supported between the upper rolling part and the lower rolling part. The main pressure source is used to output pressure to the upper rolling part and / or the lower rolling part to roll the pole piece to be rolled passing between the upper rolling part and the lower rolling part. When the main pressure source outputs pressure, the output pressure of the main pressure source will act on the upper rolling part and / or the lower rolling part, and part of the output pressure will squeeze the limiter, resulting in the actual rolling force actually acting on the pole piece to be rolled being less than the output pressure of the main pressure source. Before rolling the electrode to be rolled, relevant data such as the target thickness, initial thickness, and actual rolling force can be pre-entered to facilitate the construction of a formula model in combination with a relevant database. In other embodiments, a variety of formula models can also be constructed in advance to form a formula model database, and then the corresponding formula model can be searched from the formula model database based on the pre-entered relevant data such as the target thickness, initial thickness, and actual rolling force.

[0046] Step S302: Based on the extrusion force on the limiter during the rolling process of the pole piece to be rolled and the formula model, the output pressure of the main pressure source is adjusted to roll the pole piece to be rolled from the initial thickness to the target thickness.

[0047] During the process of rolling the electrode to be rolled, the main pressure source will continuously output pressure to roll the electrode to be rolled. During the process of the main pressure source outputting pressure, the limiter will be squeezed, and the force exerted on the limiter when being squeezed is the extrusion force. In the related feedback-type adjustment of the output pressure of the main pressure source, it mainly uses an online laser thickness gauge to feedback the thickness of the rolled electrode, and then adjusts the output pressure online so that the rolled electrode reaches the target thickness. However, the feedback-type adjustment scheme has a large hysteresis and the control accuracy is relatively rough. Compared with the feedback-type adjustment of the output pressure of the main pressure source, since the limiter is a part of the structure of the rolling equipment, the output pressure of the main pressure source is adjusted by the extrusion force exerted on the limiter and the formula model, which can quickly and accurately adjust the output pressure of the main pressure source. In the related pre-test adjustment of the output of the main pressure source, it mainly adds a thickness gauge in front of the rolling equipment. Compared with the pre-test adjustment of the output pressure of the main pressure source, there is no need to add additional equipment and instruments, that is, there is no need to increase a lot of costs.

[0048] Through the above-mentioned implementation method, before performing the rolling operation, a formula model is first constructed, and then the output pressure of the main pressure source is adjusted according to the formula model and the extrusion force exerted on the limiter to roll the pole piece to be rolled, so that the output pressure of the main pressure source can be adjusted quickly and accurately, thereby improving the consistency of the thickness of the rolled pole piece to be rolled, reducing the proportion of pole ear misalignment after winding the pole piece, and improving the consistency of the battery cell thickness.

[0049] Referring to FIG. 4 , FIG. 4 is a flow chart of an embodiment of step S301 in FIG. 3 , specifically, including the following steps S401 to S402 .

[0050] Step S401: During the rolling process of the electrode to be rolled, the extrusion force applied to the limiting member is obtained at a preset frequency to obtain a plurality of extrusion forces.

[0051] The predicted frequency can be determined according to the actual situation. For example, the preset frequency can include but is not limited to 2 times / ms, 4 times / ms or 6 times / ms, etc. In the process of rolling the pole piece to be rolled, the extrusion force on the limiter may change with the thickness of the rolled pole piece, the belt speed of the pole piece to be rolled, the pressure input by the main pressure source and / or the pressure input by the auxiliary pressure source. In the process of rolling the pole piece to be rolled, the multiple extrusion forces on the limiter in the rolling process can be obtained according to the preset frequency, so as to determine the change of the extrusion force on the limiter in the process of rolling the pole piece to be rolled.

[0052] Step S402: In response to a force difference between two squeezing forces of adjacent frequencies among the multiple squeezing forces being greater than a preset force difference threshold, the output pressure of the main pressure source is adjusted based on the force difference and a formula model.

[0053] The two extrusion forces of adjacent frequencies can be understood as the extrusion forces received twice before and after by calculating the force difference between the two extrusion forces of the adjacent frequencies, and then comparing the force difference with the preset force difference threshold. When the force difference is less than the preset force difference threshold, it can be determined that the thickness of the rolled pole piece to be rolled meets the requirements, that is, the thickness consistency is high, and there is no need to additionally adjust the output pressure of the main pressure source. When the force difference is greater than the preset force difference threshold, it can be determined that the thickness of the rolled pole piece to be rolled does not meet the requirements, that is, the thickness consistency is low. At this time, the output pressure of the main pressure source can be adjusted in combination with the force difference and the formula model. The preset force difference threshold can be set according to actual conditions. For example, the preset difference threshold can be 0.1 tons, or the preset difference threshold can be any value between 0.1 tons and 0.5 tons. Therefore, when the difference between the two extrusion forces of adjacent frequencies is greater than the preset force difference threshold, the output pressure of the main pressure source is adjusted based on the force difference and the formula model, which can more accurately adjust the output pressure of the main pressure source and improve the consistency of the thickness of the rolled pole piece to be rolled.

[0054] Furthermore, the step of adjusting the output pressure of the main pressure source based on the force difference and the formula model (step S402) includes: determining the thickness fluctuation value corresponding to the force difference based on the formula model and the force difference; and adjusting the output pressure of the main pressure source in response to the thickness fluctuation value being greater than a preset thickness threshold.

[0055] The formula model shows that the target thickness changes with the initial thickness and the actual rolling force, and the actual rolling force is related to the output pressure of the main pressure source and the extrusion force exerted on the limiter. When the force difference is determined, the force difference can be substituted into the formula model to determine the thickness fluctuation value corresponding to the force difference. Alternatively, two extrusion forces of adjacent frequencies can be substituted into the formula model respectively to obtain the target thickness value corresponding to each extrusion force, and then the two target thickness values ​​are subtracted to obtain the thickness fluctuation value. The thickness fluctuation value is then compared with the preset thickness threshold. When the thickness fluctuation value is less than the preset thickness threshold, it can be determined that the thickness of the rolled pole piece to be rolled meets the requirements, that is, the thickness consistency is high, and there is no need to additionally adjust the output pressure of the main pressure source. When the thickness fluctuation value is greater than the preset thickness threshold, it can be determined that the thickness of the rolled pole piece to be rolled does not meet the requirements, that is, the thickness consistency is low. At this time, the output pressure of the main pressure source can be adjusted in combination with the thickness fluctuation value and the formula model. The preset thickness threshold can be set according to actual conditions. For example, the preset difference threshold can be 0.3 μm, or the preset difference threshold can be any value between 0.3 μm and 0.5 μm. Thus, the thickness fluctuation value is determined by the force model and the force difference. When the thickness fluctuation value is greater than the preset thickness threshold, the output pressure of the main pressure source is adjusted. This can more accurately adjust the output pressure of the main pressure source and improve the consistency of the thickness of the rolled pole piece.

[0056] In some embodiments, after the step of adjusting the output pressure of the main pressure source based on the extrusion force exerted on the limiter during the rolling process of the pole piece to be rolled and the formula model (step S302), the control method further includes: detecting the actual thickness of the rolled pole piece to be rolled; and correcting the formula model in response to the thickness difference between the actual thickness and the target thickness being greater than a preset thickness difference threshold. The thickness of the pole piece that has been rolled can be detected by a thickness detector. The thickness detector can include but is not limited to a laser thickness detector. The thickness detector is set downstream of the rolling equipment in the belt running direction of the pole piece to be rolled, so that the actual thickness of the rolled pole piece to be rolled can be detected by the thickness detector. After the actual thickness of the pole piece to be rolled is determined, the actual thickness and the target thickness can be differenced. When the thickness difference between the two is greater than the preset thickness difference threshold, the formula model is corrected. The preset difference threshold can be set according to the actual situation. As a result, it is convenient to use the corrected formula model to adjust the output pressure of the main pressure source and improve the consistency of the thickness of the rolled pole piece to be rolled.

[0057] In some embodiments, the step of constructing a formula model (step S301) of how the target thickness of the pole piece to be rolled changes with the initial thickness and the actual rolling force includes: obtaining the target thickness, the initial thickness and the tape speed of the pole piece to be rolled; and generating a formula model based on the deformation coefficient generated by the target thickness, the initial thickness, the actual rolling force and the tape speed.

[0058] The tape speed can be understood as the walking speed of the pole piece to be rolled, and the tape speed is related to the deformation coefficient. Before the process of rolling the pole piece to be rolled needs to be executed, the target thickness, initial thickness and tape speed can be input into the relevant controller together. The controller can generate the deformation coefficient according to the tape speed, and at the same time generate a formula model according to the target thickness, initial thickness, actual rolling force and deformation coefficient. Among them, the deformation coefficient can also be related to the material of the pole piece, the gap between the upper rolling part and the lower rolling part of the rolling equipment, and the rolling equipment. Therefore, the formula model is generated by taking into account the target thickness, initial thickness, actual rolling force and tape speed at the same time, and the formula model can be used to accurately control the output pressure of the main pressure source, thereby improving the consistency of the thickness of the rolled pole piece to be rolled.

[0059] Furthermore, in the formula model, the target thickness is equal to the difference between the initial thickness and the product of the deformation coefficient and the actual rolling force. Specifically, the formula model can be expressed as follows: H = H o -αf

[0060] Where H is the target thickness, H0 is the initial thickness, α is the deformation coefficient, and f is the actual rolling difference. When the conveyor speed increases, the deformation coefficient decreases. When the conveyor speed decreases, the deformation coefficient increases.

[0061] In some embodiments, the actual crushing force is equal to the difference between the first pressure value and the second pressure value, wherein the first pressure value is equal to the product of the first coefficient and the output pressure of the main pressure source, and the second pressure value is equal to the product of the second coefficient and the extrusion force. Specifically, in this embodiment, the actual crushing force can be expressed by the following formula: f = aF1 - bF2

[0062] Among them, f is the actual rolling force, aF1 is the first pressure value, a is the first coefficient, F1 is the output pressure of the main pressure source, aF2 is the second pressure value, b is the first coefficient, and F2 is the extrusion force.

[0063] Furthermore, the actual rolling force is equal to the difference between the first pressure value and the second pressure value, the third pressure value and the gravity value of the lower rolling part, wherein the third pressure value is equal to the product of the third coefficient and the force applied by the auxiliary pressure source.

[0064] Specifically, in this embodiment, the actual rolling force can be expressed by the following formula: f = aF1-bF2-cF3-G

[0065] Among them, f is the actual rolling force, aF1 is the first pressure value, a is the first coefficient, F1 is the output pressure of the main pressure source; aF2 is the second pressure value, b is the second coefficient, F2 is the extrusion force; cF3 is the third pressure value, c is the second coefficient, F3 is the force applied by the auxiliary pressure source, and G is the gravity value of the lower rolling part.

[0066] In some practical application scenarios, when the initial thickness of the electrode to be rolled remains unchanged, the electrode tape speed increases, and the force applied to the limiter decreases. If the input pressure of the main pressure source remains unchanged, the thickness of the rolled electrode will increase. To alleviate this situation, the main pressure source can be controlled to apply a higher output pressure to keep the thickness of the rolled electrode consistent.

[0067] In some practical application scenarios, when the electrode tape speed remains unchanged, the initial thickness of the electrode to be rolled gradually increases, and the force applied to the limiter decreases. If the input pressure of the main pressure source remains unchanged, the thickness of the rolled electrode will gradually increase. To alleviate this situation, the main pressure source can be controlled to apply a higher output pressure to keep the thickness of the rolled electrode consistent.

[0068] To sum up, before performing the rolling operation, a formula model is first constructed, and then the output pressure of the main pressure source is adjusted according to the formula model and the extrusion force exerted on the limiter to roll the pole piece to be rolled. This can quickly and accurately adjust the output pressure of the main pressure source, improve the consistency of the thickness of the rolled pole piece to be rolled, reduce the proportion of pole ear misalignment after winding the pole piece, and improve the consistency of the battery cell thickness.

[0069] The above method is applied to a battery electrode thickness control device. Specifically, please refer to Figure 5 , which is a schematic block diagram of a battery electrode thickness control device according to one or more embodiments of the present application. In this embodiment, the battery electrode thickness control device 500 includes a processor 510 and a memory 520 . The memory 520 stores a computer program, and the processor 510 is configured to execute the computer program to implement the above battery electrode thickness control method.

[0070] The processor 510 may be an integrated circuit chip with signal processing capabilities. The processor 510 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The general-purpose processor may be a microprocessor or any conventional processor.

[0071] The battery electrode thickness control method of the above-mentioned embodiment can be presented in the form of a computer program. The present application proposes a computer storage medium carrying the computer program. Please refer to Figure 6. Figure 6 is a structural schematic block diagram of a computer storage medium according to one or more embodiments of the present application. The computer storage medium 600 of this embodiment includes a computer program 610, which can be executed to implement the above-mentioned battery electrode thickness control method.

[0072] The computer storage medium 600 in this embodiment can be a medium that can store program instructions, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, or it can also be a server that stores the program instructions. The server can send the stored program instructions to other devices for execution, or it can also execute the stored program instructions itself.

[0073] In addition, if the above functions are implemented as software functions and sold or used as independent products, they can be stored in a storage medium readable by a mobile terminal. That is, the present application also provides a storage device storing program data, which can be executed to implement the methods of the above embodiments. The storage device can be, for example, a USB flash drive, an optical disk, a server, etc. In other words, the present application can be embodied in the form of a software product, which includes a number of instructions for causing a smart terminal to execute all or part of the steps of the methods described in each embodiment.

[0074] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0076] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0077] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (which can be a personal computer, server, network device, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0078] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for controlling the thickness of a battery electrode, characterized in that: The control method includes: Constructing a formula model for how the target thickness of the electrode to be rolled changes with the initial thickness and the actual rolling force, wherein the actual rolling force is related to the output pressure of the main pressure source and the extrusion force exerted on the stopper; Based on the extrusion force applied to the limiter during rolling of the pole piece to be rolled and the formula model, the output pressure of the main pressure source is adjusted to roll the pole piece to be rolled from the initial thickness to the target thickness.

2. The control method according to claim 1, characterized in that: The step of adjusting the output pressure of the main pressure source based on the extrusion force applied to the limiter during the rolling of the pole piece to be rolled and the formula model includes: During the rolling process of the pole piece to be rolled, the extrusion force applied to the limiter is obtained according to a preset frequency to obtain a plurality of the extrusion forces; In response to a force difference between two adjacent frequencies of the plurality of extrusion forces being greater than a preset force difference threshold, the output pressure of the main pressure source is adjusted based on the force difference and the formula model.

3. The control method according to claim 2, characterized in that: The step of adjusting the output pressure of the main pressure source based on the force difference and the formula model includes: Determining a thickness fluctuation value corresponding to the force difference based on the formula model and the force difference; In response to the thickness fluctuation value being greater than a preset thickness threshold, the output pressure of the main pressure source is adjusted.

4. The control method according to any one of claims 1 to 3, characterized in that: After the step of adjusting the output pressure of the main pressure source based on the extrusion force applied to the limiter during the rolling of the pole piece to be rolled and the formula model, the control method further includes: Detecting the actual thickness of the rolled pole piece to be rolled; In response to a thickness difference between the actual thickness and the target thickness being greater than a preset thickness difference threshold, the formula model is modified.

5. The control method according to any one of claims 1 to 4, characterized in that: The step of constructing a formula model for how the target thickness of the pole piece to be rolled changes with the initial thickness and the actual rolling force comprises: Obtaining the target thickness, the initial thickness, and the tape speed for rolling the electrode to be rolled; The formula model is generated based on the target thickness, the initial thickness, the actual rolling force and the deformation coefficient generated by the belt speed.

6. The control method according to claim 5, characterized in that: In the formula model, the target thickness is equal to the difference between the initial thickness and the product of the deformation coefficient and the actual rolling force.

7. The control method according to any one of claims 1 to 6, characterized in that: The actual crushing force is equal to the difference between the first pressure value and the second pressure value, wherein the first pressure value is equal to the product of the first coefficient and the output pressure of the main pressure source, and the second pressure value is equal to the product of the second coefficient and the extrusion force.

8. The control method according to claim 7, characterized in that: The actual rolling force is equal to the difference between the first pressure value and the second pressure value, the third pressure value and the gravity value of the lower rolling part, wherein the third pressure value is equal to the product of the third coefficient and the force applied by the auxiliary pressure source.

9. A battery electrode thickness control device, characterized in that: The battery pole sheet thickness control device includes a processor and a memory, wherein a computer program is stored in the memory, and the processor is used to execute the computer program to implement the battery pole sheet thickness control method according to any one of claims 1 to 8.

10. A computer-readable storage medium having program instructions stored thereon, characterized in that: When the program instructions are executed by the processor, the battery electrode thickness control method according to any one of claims 1 to 8 is implemented.

11. A battery electrode thickness control system, characterized in that: The control system includes a controller and a rolling device, and the controller is used to execute the battery electrode thickness control method according to any one of claims 1 to 8 to control the rolling device to roll the electrode to be rolled.

12. The battery electrode thickness control system according to claim 11, characterized in that: The rolling equipment includes an upper rolling part, a lower rolling part, a main pressure source and a limiter, wherein the limiter is supported between the upper rolling part and the lower rolling part, and the main pressure source is used to output pressure to the upper rolling part and / or the lower rolling part to roll the pole piece to be rolled passing between the upper rolling part and the lower rolling part.

13. The battery electrode thickness control system according to claim 12, characterized in that: The rolling equipment further includes an auxiliary pressure source, which is located between the upper rolling part and the lower rolling part and is closer to the ends of the upper rolling part and the lower rolling part than the limiting member.

14. The battery electrode thickness control system according to claim 12 or 13, characterized in that: The limiting member includes a first limiting portion and a second limiting portion, the first limiting portion and the second limiting portion abut against each other in the direction of the spacing between the upper rolling portion and the lower rolling portion, and at least one of the first limiting portion and the second limiting portion includes a pressure sensor.

15. The battery electrode thickness control system according to any one of claims 11 to 14, characterized in that: The control system further comprises a thickness detector, which is located downstream of the rolling equipment in the running direction of the pole piece to be rolled.

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