Temperature closed-loop control method applied to pole piece drying and baking device

Abstract

The invention discloses a temperature closed-loop control method applied to pole piece drying and a baking device. The method comprises the following steps: acquiring a temperature signal of the surface of a running pole piece; based on the collected temperature signals, drying parameters of the pole piece are dynamically adjusted, and the drying parameters comprise at least one of the heating power, the pole piece tape walking speed and the distance between a heating element and the surface of the pole piece; and performing closed-loop adjustment on the drying parameters according to the collected temperature signal when the pole piece leaves the baking area, so that the temperature of the pole piece when the pole piece leaves the current baking oven reaches a set target value. The baking device is used for executing the method.

Description

Technical Field

[0001] This invention relates to the field of electrode production technology, and in particular to a closed-loop temperature control method and baking apparatus for electrode drying. Background Technology

[0002] In the manufacturing process of electrodes for lithium-ion batteries, the coated wet electrodes need to be dried to remove solvents. Vacuum baking technology is used because it can lower the boiling point of the solvent and improve drying efficiency, and its effect is better than atmospheric pressure baking. However, in actual production, especially for drying long strip electrodes, existing technologies still have significant bottlenecks. Due to the long drying path of the electrode and the fact that the entire drying process is completed in a single baking chamber, the internal environment of the oven is complex, with temperature and humidity gradients. This easily leads to uneven drying, with localized overheating (over-baking) or localized excessive temperature and humidity (insufficient drying). After the electrodes are removed from the oven, their overall dryness fails to meet the process requirements, which not only directly affects the consistency and performance of the product (such as damage to active materials or solvent residue), but also increases production losses such as rework or scrap due to substandard quality. Summary of the Invention

[0003] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a closed-loop temperature control method and baking apparatus for electrode drying, which helps improve the drying uniformity and final product quality consistency of electrodes during long-path baking. It enables synergistic optimization of multiple parameters in the drying process and closed-loop control throughout the entire process, thereby effectively solving the problem of unstable drying quality caused by inaccurate temperature control and uneven environment in the prior art.

[0004] In a first aspect, a temperature closed-loop control method for electrode drying according to an embodiment of the present invention includes the following steps:

[0005] Collect temperature signals from the surface of the electrode during operation; Based on the collected temperature signal, the drying parameters of the electrode are dynamically adjusted. The drying parameters include at least one of heating power, electrode conveyor speed, and distance between heating element and electrode surface. Based on the temperature signal collected when the electrode leaves the baking area, the drying parameters are adjusted in a closed loop to ensure that the temperature of the electrode reaches the set target value when it leaves the current oven.

[0006] The temperature closed-loop control method for electrode drying according to embodiments of the present invention has at least the following beneficial effects: First, the temperature signal of the electrode surface during operation is acquired in real time. This signal is a key input for the control system to perceive the real-time status of the electrode. Next, based on the acquired temperature signal, the drying parameters for the electrode are dynamically adjusted. The drying parameters include at least one of heating power, electrode conveyor speed, and distance between the heating element and the electrode surface. This step allows the control system to flexibly select the most effective adjustment dimension according to real-time operating conditions, thereby achieving immediate intervention in the drying process. Finally, based on the acquired final temperature signal of the electrode when it leaves the baking area, the aforementioned drying parameters are adjusted and calibrated in a closed loop to ensure that the temperature of the electrode reaches the preset target value when it leaves the oven, thereby consolidating and verifying the effectiveness of the entire drying process from the result.

[0007] According to the temperature closed-loop control method for electrode drying according to an embodiment of the present invention, the temperature signal acquisition includes: acquiring the signal when the electrode enters the baking area, during the baking process, and when it leaves the baking area.

[0008] According to the temperature closed-loop control method for electrode drying according to an embodiment of the present invention, the electrode passes through the baking zone in a continuous conveying manner, wherein the continuous conveying manner is that the electrode continuously enters and passes through the baking zone without interruption; or, The electrode sheet passes through the baking area in an intermittent conveying manner. The intermittent conveying includes: conveying a section of electrode sheet to the baking area and stopping it for baking, and sending it out after the section of electrode sheet has been baked, while conveying the next section of electrode sheet to the baking area.

[0009] According to an embodiment of the present invention, the temperature closed-loop control method for electrode drying includes a baking zone formed inside an oven, the baking zone comprising multiple baking sections, and the multiple baking sections being arranged in series along the length of the oven. or, The baking area is formed inside the oven and includes multiple baking sections. The multiple baking sections are stacked along the height direction of the oven, and the extension direction of the electrode sheet in the baking section is parallel to the length direction of the oven. or, The baking area is formed inside the oven and includes multiple baking sections. The multiple baking sections are stacked along the length of the oven, and the extension direction of the electrode sheet in the baking section is parallel to the height direction of the oven. In each of the baking sections, at least one of the inlet and outlet is equipped with an infrared thermometer, which is used to collect temperature signals when the electrode enters and / or leaves the corresponding baking section.

[0010] According to the temperature closed-loop control method for electrode drying according to an embodiment of the present invention, when multiple baking sections are stacked along the length or height of the oven, the electrode switches its travel path direction between two adjacent baking sections, and a heat compensation module is provided between two adjacent baking sections. The heat compensation module is used to supplement the heating of the electrode located at the point where the travel path direction is switched.

[0011] According to an embodiment of the present invention, the temperature closed-loop control method for electrode drying includes a baking section comprising multiple infrared heating modules arranged along the electrode traveling direction. Each infrared heating module includes two infrared heaters arranged opposite each other. The two infrared heaters respectively radiate and heat two surfaces of the electrode to be baked. The infrared heaters output radiant energy based on the state parameter signals of the corresponding surfaces to be baked.

[0012] The temperature closed-loop control method for electrode drying according to embodiments of the present invention further includes acquiring humidity signals of the electrode surface during operation, and performing the following adjustments independently or in combination based on the acquired temperature and / or humidity signals of the corresponding surface to be dried: Adjust the distance between the infrared heater and the corresponding surface to be baked; Adjust the output radiation energy of the infrared heater.

[0013] According to embodiments of the present invention, the temperature closed-loop control method for electrode drying performs the following adjustments independently or in combination based on real-time acquired temperature and / or humidity signals: By adjusting the conveyor belt speed of the electrode, the surface temperature and / or humidity of the electrode when it leaves the oven are kept within a preset range; Within the same baking section, by increasing or decreasing the number of activated infrared heaters, the surface temperature and / or humidity of the electrode when it leaves the oven are kept within a preset range.

[0014] According to an embodiment of the present invention, a temperature closed-loop control method for electrode drying is used to collect state parameter signals inside an oven. These state parameter signals include at least temperature and / or humidity signals distributed along the height direction within the oven. Based on the collected state parameter signals, the following adjustments are performed independently or in combination: Adjust the distance between the infrared heater and the corresponding surface to be baked; Adjust the output radiation energy of the infrared heater; Adjust the belt travel speed of the electrode.

[0015] According to an embodiment of the present invention, a temperature closed-loop control method for electrode drying actively regulates the gas environment inside the oven based on the collected state parameter signals inside the oven. The active regulation includes performing any of the following methods independently or in combination: Cooling medium is introduced into the baking section where the temperature is too high; Actively discharge the gas medium in the baking section where the temperature is higher than the preset value; Actively release the gas medium in the baking section where the humidity is higher than the preset value.

[0016] Secondly, according to an embodiment of the present invention, a baking apparatus is used to perform the above-described temperature closed-loop control method, comprising: An oven is formed inside a baking zone. Both the inlet and outlet of the baking zone are equipped with infrared thermometers, which are used to detect the surface temperature of the electrode sheets when they enter and leave the baking zone. A baking module is disposed within the baking area. The baking module includes multiple baking sections arranged along a first direction. The electrode can pass through the baking sections. At least one of the baking sections is provided with an infrared thermometer, which is used to detect the surface temperature of the electrode within the baking section.

[0017] The baking apparatus according to the embodiments of the present invention has at least the following beneficial effects: By constructing a global closed-loop control with the outlet temperature as the final criterion, the drying results are directly fed back to the process regulation, which can systematically correct the cumulative errors caused by fluctuations in incoming materials, equipment state drift, etc., effectively avoiding the "over-drying" and "under-drying" problems commonly found in traditional open-loop or partial closed-loop control, and reliably ensuring the consistency of the dryness of each batch of products.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is the overall logic diagram of the temperature closed-loop control method according to an embodiment of the present invention; Figure 2 This is a logic diagram of the basic closed-loop and full-process monitoring of the temperature closed-loop control method in an embodiment of the present invention; Figure 3 This is a logic diagram of the continuous delivery control of the temperature closed-loop control method according to an embodiment of the present invention; Figure 4 This is a logic diagram of the intermittent delivery control of the temperature closed-loop control method according to an embodiment of the present invention; Figure 5 This is a logic diagram of the superposition arrangement and thermal compensation of the temperature closed-loop control method in an embodiment of the present invention. Figure 6 This is a logic diagram of the dual-sided independent temperature and humidity control method of the temperature closed-loop control method in an embodiment of the present invention; Figure 7 This is a logic diagram of environmental monitoring and active intervention in the temperature closed-loop control method according to an embodiment of the present invention; Figure 8 This is a logic diagram of the speed and zone control of the temperature closed-loop control method according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the first superimposed layout structure of the baking section according to an embodiment of the present invention; Figure 10 This is a schematic diagram of a second superimposed layout structure of the baking section according to an embodiment of the present invention; Figure 11 This is a partial structural diagram of the baking apparatus according to an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: Electrode 100; Baking section 200; Infrared heater 300; Thermal compensation module 400; Oven 500; Infrared thermometer 600. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0023] In the description of the invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. If the terms "first" and "second" are used, they are only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0025] In long-path baking, relying solely on process temperature settings or open-loop control is insufficient to overcome interference from incoming material fluctuations and equipment thermal inertia. This causes the final temperature of electrode 100 upon leaving the oven (a core indicator of dryness) to deviate from the set value, resulting in inconsistent dryness within batches and posing a risk of over- or under-baking. Therefore, referring to... Figure 1 This invention provides a closed-loop temperature control method for electrode drying, comprising the following steps: Collect the temperature signal of the surface of electrode 100 during operation; Based on the collected temperature signal, the drying parameters of the electrode 100 are dynamically adjusted. The drying parameters include at least one of the following: heating power, electrode 100 conveyor speed, and distance between the heating element and the surface of the electrode 100. Based on the temperature signal collected when the electrode 100 leaves the baking area, the drying parameters are adjusted in a closed loop so that the temperature of the electrode 100 when it leaves the current oven reaches the set target value.

[0026] It is understood that the technical solution provided in this application constructs a closed-loop control system with the surface temperature of the electrode 100 as the feedback core. The system first collects real-time temperature data of the electrode 100 surface being conveyed using a temperature sensor (such as an infrared thermometer 600) installed inside the oven. This real-time data is transmitted to a central controller (such as a PLC). The controller has preset process temperature curves for each stage and a final target outlet temperature value. The controller compares the collected real-time temperature with the set value; if a deviation exists, it calculates the adjustment amount for at least one drying parameter using a control algorithm (such as a PID algorithm). Adjustable parameters include: the heating power of the infrared heating tube or radiation plate, the rotational speed of the roller motor driving the electrode 100 (i.e., the electrode 100 conveyor speed), and the distance between the heating element controlled by a servo slide or cylinder and the surface of the electrode 100. For example, if a temperature below the set value is detected at a certain point, the controller can instruct to increase the heating power in that area, or instruct the displacement mechanism to move the heater slightly closer to the electrode 100. Finally, when electrode 100 reaches the exit of the baking zone, the temperature sensor at the exit collects its final temperature. Based on this final signal, the controller performs a final, comprehensive calibration of all the aforementioned adjustments to ensure that the average temperature or key point temperature of the entire electrode 100 when leaving the oven meets the preset target. This establishes a global temperature closed loop from process to exit, changing the traditional baking equipment's mode of relying solely on process temperature control or open-loop operation. By using the exit temperature as the final evaluation criterion and feeding back to adjust process parameters, the system can systematically correct the drying endpoint deviation caused by factors such as incoming material fluctuations and equipment state drift, significantly improving the consistency of the drying endpoint of a batch of products and providing core control logic for solving the problems of "over-baking" or "under-baking".

[0027] Relying solely on temperature feedback from within the baking section 200 or a single outlet, the control system is unpredictable regarding the incoming material status, exhibits a lag in responding to process disturbances, and cannot correlate the final result with specific process segments, thus limiting the predictability, timeliness, and accurate traceability of the control.

[0028] Therefore, in further improvements to this application, reference is made to... Figure 2 The temperature signals collected include those collected when the electrode 100 enters the baking area, during the baking process, and when it leaves the baking area.

[0029] Understandably, this technical solution deploys a multi-point temperature monitoring network in the control system. A thermometer is installed at the oven's inlet to collect the initial temperature of the electrode 100 upon entry; thermometers are installed at multiple key locations inside the oven (such as the midpoints of each heating zone) to collect real-time temperatures during the baking process; and a thermometer is installed at the oven's outlet to collect the final temperature. The controller simultaneously receives signals from these three or more points. The inlet temperature is used to determine the incoming material's condition; if the inlet temperature is too low, the controller can pre-instruct the preheating zone to increase heating. The process temperature is the primary basis for real-time, dynamic control, used to quickly respond to local fluctuations within the oven. The outlet temperature serves as the final feedback in the closed loop and a verification point for process achievement. These three data points together constitute a complete time series, enabling the controller not only to perform point-to-point adjustments but also to predict and compensate for trend changes. By implementing full-process temperature monitoring at the inlet, process, and outlet, the control system obtains a temperature profile of the electrode 100 throughout its drying lifecycle. This helps to achieve more advanced pre-conditioning and more precise process control, avoiding the lag of relying solely on single-point feedback, making temperature management throughout the drying process more stable and smooth, and further improving process stability and product quality uniformity.

[0030] In continuous high-speed production, how can we achieve real-time and dynamic adjustment of the drying state of the moving intermediate electrode 100 without interrupting the production cycle, so as to maintain stable quality under high production capacity?

[0031] Therefore, this application further proposes an embodiment regarding the transport of the electrode 100, referring to... Figure 3 The electrode 100 passes through the baking area in a continuous conveying manner, meaning that the electrode 100 continuously enters and passes through the baking area without interruption.

[0032] Understandably, in this technical solution, the electrode 100 is released by the unwinding machine and continuously and uninterruptedly passes through the entire baking area inside the oven via the traction rollers at a constant or adjustable speed. The control system continuously collects surface temperature signals of the electrode 100 during its continuous movement. Based on these dynamically changing signals, the controller calculates and outputs adjustment commands in real time. For example, when an abnormal temperature is detected in a section of the electrode 100, the controller will adjust the power or distance of the corresponding heater in real time as that section of the electrode 100 moves below it. The entire control process is synchronized with the continuous operation of the production line, requiring the control algorithm to have rapid response capabilities and the ability to compensate for conveying delays. This technical solution is suitable for high-efficiency, high-volume continuous production lines. It can seamlessly connect with the upstream coating process, achieving uninterrupted production and maximizing equipment utilization. Dynamic closed-loop control ensures that even under continuous high-speed operation, the drying state of the electrode 100 can be finely adjusted in real time to maintain stable product quality, making it particularly suitable for the large-scale manufacturing of standardized products.

[0033] Alternatively, for electrodes with thick coatings, special materials, or those requiring extremely high drying uniformity, the heating time under continuous conveying is fixed and the control window is short, making it difficult to achieve sufficient, uniform, and depth-adjustable drying treatment.

[0034] Therefore, this application further proposes another embodiment regarding the transport of the electrode 100, referring to... Figure 4 The electrode 100 passes through the baking area in an intermittent conveying manner. The intermittent conveying includes: conveying a section of electrode 100 to the baking area and stopping it for baking, and sending it out after the section of electrode 100 has been baked, while conveying the next section of electrode 100 to the baking area.

[0035] Understandably, this technical solution adopts a "stepping-stationary-baking" cyclical mode. Specifically, the conveying mechanism pulls a specific length of wet electrode sheet 100 into the baking area and then stops. At this time, the electrode sheet 100 remains stationary in the oven. The control system is activated to centrally heat and precisely control the temperature of this stationary section. The controller can perform depth adjustment without conveying interference during the stationary period based on temperature and humidity signals from multiple measuring points on the electrode sheet 100, for example, repeatedly adjusting the heater distance until the temperature is uniformly achieved. After the section is baked, the conveying mechanism sends it out of the oven and immediately feeds in the next wet electrode sheet 100, starting the next cycle. The feeding and discharging actions can be completed synchronously in a short time. The intermittent conveying method provides each electrode sheet 100 with sufficient heating and leveling time without time constraints. The control system can perform "meticulous" control on the stationary electrode sheet 100, which is particularly beneficial for drying thick coatings, high solid content, or heat-sensitive materials, achieving better drying uniformity and consistency. Although the average production capacity may be lower than that of continuous production, it has a clear advantage in scenarios that require the highest single-piece quality or that handle special materials.

[0036] In some embodiments, a baking zone is formed inside an oven, and the baking zone includes a plurality of baking sections 200, which are arranged in series along the length of the oven.

[0037] Understandably, the entire oven interior is divided into multiple sequentially arranged baking sections 200 by physical partitions or functional zones, such as preheating, heating, isothermal, and cooling sections. The electrode 100 passes through these series-connected baking sections 200 in a straight line. Each baking section 200 is equipped with an independent heater and temperature control system, allowing for different target temperatures to be set, collectively forming a preset temperature process curve. Temperature sensors at the inlet or outlet of each baking section 200 monitor the temperature of the electrode 100 entering and exiting that section. The controller adjusts the heating parameters of that section based on this signal, achieving a closed-loop control within the section. Simultaneously, the outlet temperature of the previous section serves as a reference for feedforward adjustment by the controller of the next section. The series arrangement structure is simple, easy to understand, and easy to maintain. By decomposing long-distance drying into multiple independent short-range control zones, the difficulty of achieving a uniform temperature field within a single long cavity is significantly reduced. The temperature gradient of each section can be flexibly set and precisely controlled to adapt to the process requirements of different solvent evaporation stages, making it a classic and effective layout for achieving programmed temperature-controlled drying.

[0038] Alternatively, when the length of the production site is limited, traditional long linear series ovens cannot be installed. When a layout scheme that can extend the effective baking path within a limited length is needed, in some embodiments, as shown in the figure, the baking area is formed inside the oven. The baking area includes multiple baking sections 200, which are stacked along the height of the oven. The extension direction of the electrode 100 inside the baking section 200 is parallel to the length direction of the oven.

[0039] Understandably, referring to Figure 9 The oven has multiple independent baking sections 200 arranged vertically (height direction), with layers stacked one on top of the other. Within each baking section 200, the electrode 100 still travels horizontally along the length of the oven. The electrode 100 enters from the entrance of the first layer at the bottom of the oven, passes horizontally through that layer, and is guided to the entrance of the second layer directly above it by a vertical turning mechanism (such as lifting rollers or guide rails) located at the other end (or the same end) of the oven. Then, within the second layer, it travels in the opposite horizontal direction (or in the same direction). This process is repeated, with the electrode 100 passing through all the stacked baking sections 200 sequentially via a path of "horizontal travel – vertical layer change – horizontal travel". Each baking section 200 is an independent temperature control unit. By increasing the height of the equipment without significantly increasing the equipment's ground projection length, the effective baking path is multiplied. It fully utilizes the generally available vertical space in factories, solving the problem of not being able to install long ovens due to site length limitations, and achieving long-path drying in compact spaces.

[0040] Alternatively, in some embodiments, refer to Figure 10The baking area is formed inside the oven and includes multiple baking sections 200. The multiple baking sections 200 are stacked along the length of the oven, and the extension direction of the electrode 100 inside the baking section 200 is parallel to the height direction of the oven.

[0041] It is understandable that multiple baking sections 200 are arranged side-by-side along the length of the oven in a horizontal plane, but they may partially or completely overlap (stack) each other in space. Inside each baking section 200, the electrode 100 travels vertically along the height of the oven. For example, the electrode 100 enters from the bottom of the first baking section 200 on one side of the oven, travels vertically upward, reaches the top of that section, and is then fed into the top of the adjacent, length-stacked second baking section 200 via a horizontal turning mechanism, and then travels vertically downward within the second baking section 200. In this way, the electrode 100 travels through all the baking sections 200 stacked along the length in a zigzag or serpentine path of "vertical upward - horizontal section change - vertical downward". Each baking section 200 is also an independently temperature-controlled vertical channel. Stacking the baking sections 200 along the length and changing the direction of travel of the electrode 100 to vertical is suitable for situations where the equipment installation space is long and narrow but the width is limited. The vertical flow path facilitates natural convection of hot air and allows heaters to be arranged along both sides of the vertical channel, simplifying the design for heating uniformity of the wide electrode 100. It achieves highly efficient drying within a limited footprint by utilizing height and clever path planning.

[0042] It is important to note that, in particular, the reference Figure 9 and Figure 10 In any of the above embodiments regarding the conveyor belt method for the electrode 100, an infrared thermometer 600 is provided at least at one of the inlet and outlet of each baking section 200. The infrared thermometer 600 is used to collect temperature signals when the electrode 100 enters and / or leaves the corresponding baking section 200. The signal provided by the thermometer directly reflects the effect of the process execution in that section (outlet temperature) or the incoming material status (inlet temperature). Based on this, the controller precisely adjusts the heating parameters of that section to ensure that each baking section 200 can stably reach its set target, thereby ensuring that the process in each locality is controlled regardless of the overall path layout.

[0043] Furthermore, in the technical solution where the baking section 200 is stacked (whether stacked along the height direction or along the length direction) and the electrode 100 needs to switch the direction of travel between sections, the reversing area is easily a weak link in heating because it is separated from the main heating baking section 200 and the guide roller with a lower contact temperature, which affects the overall drying uniformity.

[0044] Therefore, this application further proposes, with reference to Figure 9 or Figure 10 At the same time, in conjunction with reference Figure 5When multiple baking sections 200 are stacked along the length or height of the oven, the electrode 100 switches its travel path direction between two adjacent baking sections 200, and a heat compensation module 400 is provided between two adjacent baking sections 200. The heat compensation module 400 is used to supplement the heating of the electrode 100 located at the point where the travel path direction is switched.

[0045] Understandably, the vertical turning points between layers or the horizontal turning points between segments of the electrode 100 are areas prone to temperature loss. Near these specific turning points, the system is equipped with a heat compensation module 400. When the electrode 100 reaches a turning point, the heating of its main baking section 200 may have weakened or stopped. At this time, the control system, based on position sensing or program timing, activates the heat compensation module 400 at that turning point to provide brief, directional supplementary heating to the electrode 100 that is passing through or has just passed through the turning point. This compensates for the heat loss caused by the interruption of heat dissipation and heat input in that area, helping to solve the "thermal discontinuity" problem caused by the physical turning structure in the stacked layout. It ensures that the heat input received by the electrode 100 is continuous and smoothly transitioned throughout the potentially very tortuous baking path, eliminating potential localized drying defects caused by turning points, thus ensuring the uniformity of drying of the final product even under complex spatial folding paths.

[0046] In some embodiments, refer to Figure 9 or Figure 10 The baking section 200 includes multiple infrared heating modules arranged along the traveling direction of the electrode 100. Each infrared heating module includes two infrared heaters 300 arranged opposite each other. The two infrared heaters 300 respectively radiate and heat the two surfaces of the electrode 100 to be baked. The infrared heaters 300 output radiant energy based on the state parameter signals of the corresponding surfaces to be baked.

[0047] Understandably, within any baking section 200, several heating units, hereinafter referred to as infrared heating modules, are installed along the direction of travel of the electrode 100. The core of each module is two infrared heaters 300 mounted face-to-face, with a gap between them for the electrode 100 to pass through. As the electrode 100 passes through, its upper and lower surfaces are simultaneously heated by infrared radiation from these two heaters. Crucially, each heater is connected to an independent or zone-controlled power supply, and its operating state (e.g., power) is regulated by a controller. The controller receives temperature signals from temperature measuring points on the upper and lower surfaces of the electrode 100 and then independently determines the amount of radiant energy each heater should output. For example, if the upper surface temperature is too high, the power of the upper heater is reduced; if it is necessary to enhance the heating of the lower surface, the power of the lower heater is increased, thus upgrading the drying of the electrode 100 from "single-sided" or "mixed" heating to "double-sided independent controllable radiant heating." This significantly improves heat transfer efficiency and uniformity. More importantly, it provides the hardware foundation for differentiated and refined control based on the real-time state of the double-sided electrode 100, which is the key to achieving high-quality and uniform drying.

[0048] Sometimes, relying solely on temperature signals is insufficient to accurately determine the drying process (such as the solvent evaporation stage). Furthermore, when the drying degree on both sides of the electrode 100 is inconsistent, how can more precise and targeted control be achieved?

[0049] Therefore, this application further proposes, with reference to Figure 6 It also includes collecting the humidity signal of the surface of the electrode 100 during operation, and adjusting the distance between the infrared heater 300 and the corresponding surface to be baked and / or adjusting the output radiation energy of the infrared heater 300 based on the collected temperature signal and / or humidity signal of the corresponding surface to be baked.

[0050] Understandably, this technical solution adds monitoring of the surface humidity of the electrode 100 based on the aforementioned technical solution. Within each baking section 200, in addition to the infrared thermometer 600, an online humidity sensor (such as a near-infrared or capacitive sensor) is also installed to collect humidity signals from the upper and lower surfaces of the electrode 100, respectively. The control system now possesses real-time data in both temperature and humidity dimensions. Based on this richer information, the controller can execute the following control strategies: The first strategy is distance adjustment: the control system analyzes the relationship between the temperature and humidity signals of the surface to be baked. When it is determined that the drying process of a certain surface is mainly driven by solvent evaporation demand, and the surface temperature is already within a reasonable range, the controller will prioritize adjusting the heating distance. By controlling the displacement mechanism of the heater on that side, it is moved closer to the surface of the electrode 100, thereby increasing the radiative heat flux density without significantly increasing the substrate temperature, and specifically accelerating the solvent evaporation process in that area.

[0051] The second approach is an energy regulation strategy: the control system can also dynamically set or adjust the output power of the infrared heater 300 based directly on the collected temperature and humidity composite signals. For example, the humidity signal can be introduced as a feedforward or compensation variable into the power control algorithm, enabling the heater's radiant energy output to respond more sensitively to the actual needs of the drying process, thus achieving refined management of the drying power.

[0052] These adjustments can be made independently for the upper and lower surfaces, or in combination (such as simultaneously adjusting the distance and increasing the power), thereby achieving independent, precise, and adaptive control of the double-sided drying process of the electrode 100.

[0053] However, when faced with large fluctuations in the amount of incoming material coated, drastic changes in the environment, or the need to quickly correct the overall drying progress, simply adjusting the heater parameters (distance, power) may not be fast enough or effective enough.

[0054] Therefore, this application further proposes, with reference to Figure 8 Based on the acquired temperature and / or humidity signals, the adjustment also includes at least one of the following methods: By adjusting the conveyor belt speed of electrode 100, the surface temperature and / or humidity of electrode 100 when it leaves the oven are kept within a preset range; Within the same baking section 200, by increasing or decreasing the number of activated infrared heaters 300, the surface temperature and / or humidity of the electrode 100 when it leaves the oven are kept within a preset range.

[0055] Understandably, this solution provides two macroscopic and regional supplementary control methods: The first is adjusting the conveyor belt speed. The control system continuously monitors the temperature and / or humidity of the electrode 100 at the outlet. If the average value is found to deviate continuously from the set range, the controller will determine that the current overall drying progress is too fast or too slow. At this time, it will issue a command to adjust the speed of the drive motor, thereby changing the conveyor belt speed of the entire electrode 100. Increasing the speed can shorten the total residence time to correct the "over-drying" trend; decreasing the speed can extend the total residence time to correct the "under-drying" trend. This is a global and powerful intervention method. The second is increasing or decreasing the number of heaters activated. Within the same baking section 200, multiple sets of infrared heating modules are usually arranged side by side along the width direction of the electrode 100. When the control system detects significant temperature unevenness (such as local "hot spots") in the width direction of the baking section 200 through temperature imaging or zoning sensors, it can selectively shut down or reduce the temperature of one or more sets of heaters corresponding to the "hot spots" while keeping the heaters in other areas working normally. Conversely, if a localized "cold zone" is detected, the standby heater for that area can be activated independently. This is a regional, precise power allocation method. These two adjustment methods greatly enhance the adaptability of the control system. Belt speed adjustment provides a "master valve" for controlling the total drying time, enabling rapid responses to significant process fluctuations. Increasing or decreasing the number of heaters provides the ability to finely allocate the heat field distribution in a two-dimensional plane (length and width), effectively eliminating localized overheating or underheating, forming a three-dimensional, multi-level control system from global to local, from time to space.

[0056] In addition, due to factors such as rising hot air and accumulating solvent vapor, a temperature gradient and a humidity gradient will be formed inside the oven from top to bottom. This unevenness of the background environment will interfere with the temperature control effect of the baking section 200 itself, resulting in inconsistent actual process conditions in the baking sections 200 located at different heights or positions.

[0057] Therefore, this application further proposes to collect state parameter signals inside the oven, which include at least temperature and / or humidity signals at multiple different locations distributed along the height direction inside the oven. Based on the collected state parameter signals inside the oven, the distance between the infrared heater 300 and the corresponding surface to be baked is adjusted and / or the output radiation energy of the infrared heater 300 is adjusted and / or the belt speed of the electrode 100 is adjusted.

[0058] Understandably, this technical solution installs environmental monitoring sensors at multiple representative locations inside the oven, including high, middle, and low points, to collect real-time air temperature and humidity data within the oven cavity. The central controller analyzes this data and plots a temperature and humidity distribution map inside the oven. Based on this map, the controller performs "environmental compensation" on the original process control. For example, if the ambient temperature at the top of the oven is consistently 5°C higher than at the bottom, the controller will apply a negative bias (e.g., reduce by 2%) to the set power of all baking sections 200 at the top or heaters located above, or automatically slightly increase their distance from the electrode 100. Similarly, if excessive humidity is detected in a certain area, potentially affecting evaporation efficiency, the controller can pre-emptively adjust the power of the heaters or the conveyor belt speed in that area for compensation. This compensation is superimposed on the original closed-loop control based on the surface signal of the electrode 100, achieving a leap from "ignoring environmental interference" to "actively sensing and compensating for environmental interference." It enables the control system to overcome the inherent physical inhomogeneity inside the oven, ensuring that the effective thermal process (net heating effect) experienced by the electrode 100 is consistent in different spatial locations. This greatly improves the overall equipment's ability to handle consistency, especially in tall or complex ovens.

[0059] Furthermore, when the air temperature in a specific baking section 200 inside the oven rises sharply due to abnormal heating power, poor heat dissipation, or local overheating of the electrode 100, exceeding the safe process range, relying solely on indirect methods such as reducing heater power or increasing heating distance will result in slow cooling speed and will not be able to quickly curb local high temperatures. This may lead to over-baking of the electrode 100 in that area or even cause safety hazards.

[0060] Therefore, this application further proposes, with reference to Figure 7 Based on the collected state parameter signals inside the oven, active regulation is performed on the gas environment inside the oven. Active regulation includes: introducing a cooling medium into the baking section 200 where the temperature is too high.

[0061] It is understood that each independent baking section 200 (or critical area) of the oven is pre-installed with independent air supply ducts and controllable valves on its side walls or top. The air supply ducts are connected to a treated source of dry, cold air or an inert gas (such as nitrogen). When a temperature sensor located inside the oven detects that the air temperature in that area exceeds a preset first-level alarm threshold, the central controller immediately sends an opening command to the air supply duct valve in that area. Pre-cooled dry gas is rapidly introduced into the high-temperature area at a certain flow rate. This injection of low-temperature gas, through direct mixing and convection, quickly dilutes and lowers the temperature of the hot air in that localized area. Simultaneously, the introduction of dry gas also helps reduce the relative humidity in that area, aiding solvent evaporation. The valve opening duration and gas flow rate can be dynamically adjusted by the controller based on the temperature drop rate and the set temperature until the temperature in that area returns to a safe range. This technical solution provides a "point-to-point" physical cooling method for localized high temperatures, with a response speed far faster than regulating the heater. It can quickly remove heat from dangerous high-temperature areas, effectively preventing overheating of the electrode and damage to active materials caused by localized temperature runaway, and improving the overall process safety of the system. This is an important supplement and enhancement to traditional temperature control methods.

[0062] Alternatively, when a certain area inside the oven experiences abnormal heating or heat accumulation forming a stable high-temperature gas mass, simply introducing cold air may cause internal airflow turbulence, and the cooling efficiency is limited by the mixing speed. A more thorough method is needed to directly remove the heat source (high-temperature gas) from the system. To this end, this application further proposes to actively regulate the gas environment inside the oven based on the collected state parameter signals. This active regulation includes: actively discharging the gas medium in the baking section 200°C where the temperature is higher than a preset value.

[0063] Understandably, the system has exhaust pipes with valves installed in the high-temperature-prone areas (usually the top) of each baking section of the oven, 200°C. These pipes lead directly to the external exhaust gas treatment system or the atmosphere. When the temperature sensor in this area detects that the air temperature consistently exceeds the preset second-level (higher) threshold, or the temperature rise rate is abnormal, the controller determines that a "hot spot" air mass has formed. At this time, the controller instructs the valve on the exhaust pipe in this area to open, actively extracting the hot air from the oven directly using the pressure difference between the inside and outside of the oven or auxiliary suction devices, quickly discharging the hottest gas. The exhaust intensity (valve opening, suction power) can be proportionally adjusted according to the degree of temperature exceedance. Directly discharging hot gas is the most direct and highly efficient way to remove heat. It can quickly break up localized heat buildups and prevent heat from spreading to adjacent areas, making it particularly suitable for handling sudden severe overheating caused by equipment failure or process abnormalities. This method helps maintain the stability of the overall thermal environment inside the oven and avoids contamination of the overall process by localized high temperatures.

[0064] Alternatively, during the drying process, a certain baking section 200 may experience excessively high solvent vapor concentration (humidity) in the local air due to concentrated solvent evaporation or poor airflow organization. High humidity reduces the solvent evaporation rate and may even reach the dew point, causing condensation, which is detrimental to drying and may lead to re-moistening or uneven drying of the electrode 100. Therefore, this application further proposes to actively regulate the gas environment inside the oven based on the collected state parameter signals. This active regulation includes actively discharging the gas medium from the baking section 200 where the humidity exceeds a preset value.

[0065] Understandably, humidity sensors are installed in each baking section 200 within the oven, and exhaust vents with valves are located in areas prone to moisture accumulation (such as the outlet side and bottom of baking section 200). When the controller detects through the humidity sensor that the solvent vapor concentration (absolute humidity or relative humidity) in a certain area exceeds the upper limit allowed by the process, it determines that the humidity in that area is too high. The controller then instructs the valve of the corresponding exhaust vent to actively expel the solvent-rich, high-humidity air from the oven. To maintain pressure balance within the oven and promote air renewal, the system typically introduces dry air or inert gas from other locations within the oven (such as the air inlet) while dehumidifying. This "wet out, dry in" replacement process rapidly reduces the absolute humidity of the local environment, disrupts the gas-liquid balance, and thus accelerates the continuous evaporation of solvent from the surface of the electrode 100 in that area. Active dehumidification directly targets the core of the drying process—removing solvent vapor—effectively solving the drying bottleneck problem caused by excessively high local humidity and preventing evaporation from slowing down or even stopping due to environmental saturation. By rapidly reducing the local dew point, the drying process is ensured to always be carried out under efficient mass transfer conditions, which is crucial for improving the overall drying rate and uniformity, especially for drying high-boiling-point solvents or thick coatings.

[0066] Alternatively, under more complex abnormal operating conditions, a localized area of ​​the oven may simultaneously experience severely excessive temperature and humidity, or a single control method may be insufficient. Multiple physical methods need to work together to restore environmental parameters to normal as quickly and effectively as possible. Therefore, this application further proposes to actively control the gas environment within the oven based on the collected state parameter signals. This active control includes independently or in combination the following methods: Cooling medium is introduced into the baking section 200 where the temperature is too high; Actively discharge gas medium in the baking section with a temperature 200°C higher than the preset value; Actively release the gas medium in the baking section with humidity exceeding the preset value by 200.

[0067] It is understandable that combined execution is a flexible application and logical integration of the three basic control methods mentioned above: introducing cooling medium, actively discharging high-temperature gas, and actively discharging high-humidity gas. The central controller performs comprehensive diagnosis based on real-time collected temperature and humidity signals and their changing trends, and executes preset or dynamically calculated multi-mode control strategies. Specifically, it can be divided into the following collaborative control logics: The first method is parallel collaborative control. When sensor data in a certain area indicates that both high temperature and high humidity conditions are simultaneously present, the controller issues commands in parallel, simultaneously activating the exhaust valve (to actively discharge the high-temperature or high-humidity gas in that area) and the air supply valve (to introduce a dry cooling medium into that area). This system actively removes the high-temperature, high-humidity mixture through exhaust, while simultaneously injecting low-temperature, dry gas for replacement and cooling. This parallel gas replacement strategy aims to achieve synchronous and rapid correction of the temperature and humidity parameters in that area.

[0068] The second type is threshold-based progressive control, where the system presets multiple alarm and action thresholds for temperature and humidity parameters. For example, when a parameter exceeds the first-level (warning) threshold, the controller only initiates a low-intensity single-mode adjustment (such as introducing cooling medium at a low flow rate). If the parameter continues to deteriorate and reaches the second-level (intervention) threshold, the controller will initiate a higher-intensity single-mode adjustment (such as performing active exhaust), or initiate the aforementioned parallel coordinated control mode (simultaneously performing cooling medium introduction and active exhaust). This mechanism, which progressively increases the intervention intensity according to the severity of the exceedance, achieves a balance between precise fine-tuning of small fluctuations and effective suppression of large disturbances.

[0069] The third type is time-sequential control. In scenarios requiring rapid suppression of peak values ​​followed by fine-tuning, the controller employs a strategy of executing different modes sequentially over time. For example, it first performs active exhaust control for a short period (e.g., 10 seconds) to remove most of the excess heat in the most direct way; then it switches to controlling the introduction of cooling medium to continuously and finely regulate and maintain the temperature of the area. This phased control strategy optimizes response speed and control accuracy.

[0070] The aforementioned combined execution method demonstrates the high level of intelligence and strategic nature of the proactive environmental control system. It enables the control system to automatically select and execute single or combined optimal intervention strategies based on multi-dimensional real-time operating information, greatly enhancing the system's comprehensive ability to handle complex and sudden abnormal operating conditions. This ensures that the drying process can quickly recover and stabilize within the optimal process window even when faced with drastic fluctuations in the local environment, thus providing a higher level of guarantee for the stability of the final product quality and the continuity of the production process.

[0071] like Figure 11As shown, in another embodiment, this application also provides a baking apparatus for performing the above-described control method. Specifically, the baking apparatus includes an oven 500, which forms a baking zone inside. Infrared thermometers 600 are installed at both the inlet and outlet of the baking zone. The infrared thermometers 600 are used to detect the surface temperature of the strip workpiece when it enters and leaves the baking zone. A baking module is disposed within the baking zone. The baking module includes multiple baking sections 200 arranged along a first direction. The strip workpiece can pass through the baking sections 200. At least one baking section 200 is equipped with an infrared thermometer 600, which is used to detect the surface temperature of the strip workpiece within the baking section 200. Specifically, the oven 500 constitutes a closed process cavity (baking zone). High-precision infrared thermometers 600 are fixedly installed at its inlet and outlet. The inlet thermometer is used to collect the initial temperature of the strip workpiece upon entry, providing a reference for the incoming material status to the control system. The outlet thermometer is used to collect the final temperature of the workpiece after baking, serving as the final feedback point for achieving global closed-loop control. It can be understood that the oven 500 contains a baking module, the main body of which consists of multiple independent baking sections 200 arranged along a certain direction (the first direction, which can be selected according to the design as length, height, or width). These baking sections 200 constitute the specific channels and heating zones for the workpiece. To achieve precise monitoring of the baking process, infrared thermometers 600 are also installed at the inlet or outlet of at least one baking section 200 (typically each baking section 200). These "process thermometers" are used to monitor the surface temperature of the workpiece in real time at each process stage, providing direct signal input for the independent closed-loop control or inter-section coordinated control of each baking section 200. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A closed-loop temperature control method applied to electrode drying, characterized in that, Includes the following steps: The temperature signal of the surface of the electrode (100) during operation is collected; Based on the collected temperature signal, the drying parameters of the electrode (100) are dynamically adjusted. The drying parameters include at least one of the following: heating power, electrode (100) conveyor speed, and distance between heating element and electrode (100) surface. Based on the temperature signal collected when the electrode (100) leaves the baking area, the drying parameters are adjusted in a closed loop so that the temperature of the electrode (100) when it leaves the current oven reaches the set target value.

2. The temperature closed-loop control method for electrode drying according to claim 1, characterized in that, Temperature signals are collected when the electrode (100) enters the baking area, during the baking process, and when it leaves the baking area.

3. The temperature closed-loop control method for electrode drying according to claim 1 or 2, characterized in that, The electrode (100) passes through the baking area in a continuous conveying manner, wherein the electrode (100) enters and passes through the baking area continuously without interruption; or, The electrode (100) passes through the baking area in an intermittent conveying manner. The intermittent conveying includes: conveying a section of electrode (100) to the baking area and stopping it for baking, and sending it out after the section of electrode (100) has been baked, while conveying the next section of electrode (100) to the baking area.

4. The temperature closed-loop control method for electrode drying according to claim 1 or 2, characterized in that, The baking area is formed inside the oven and includes multiple baking sections (200), which are arranged in series along the length of the oven. or, The baking area is formed inside the oven and includes multiple baking sections (200). The multiple baking sections (200) are stacked along the height direction of the oven, and the extension direction of the electrode sheet (100) in the baking section (200) is parallel to the length direction of the oven. or, The baking area is formed inside the oven and includes multiple baking sections (200). The multiple baking sections (200) are stacked along the length of the oven and the extension direction of the electrode sheet (100) inside the baking section (200) is parallel to the height direction of the oven. In each of the baking sections (200), at least one of the inlet and outlet is provided with an infrared thermometer (600), which is used to collect the temperature signal when the electrode (100) enters and / or leaves the corresponding baking section (200).

5. The temperature closed-loop control method for electrode drying according to claim 4, characterized in that, When multiple baking sections (200) are stacked along the length or height of the oven, the electrode (100) switches its travel path direction between two adjacent baking sections (200), and a heat compensation module (400) is provided between two adjacent baking sections (200). The heat compensation module (400) is used to supplement the heating of the electrode (100) located at the point where the travel path direction is switched.

6. The temperature closed-loop control method for electrode drying according to claim 5, characterized in that, The baking section (200) includes multiple infrared heating modules arranged along the traveling direction of the electrode (100). Each infrared heating module includes two infrared heaters (300) arranged opposite to each other. The two infrared heaters (300) radiate and heat the two surfaces of the electrode (100) to be baked, respectively. The infrared heaters (300) output radiation energy based on the state parameter signals of the corresponding surfaces to be baked.

7. The temperature closed-loop control method for electrode drying according to claim 6, characterized in that, It also includes acquiring humidity signals from the surface of the electrode (100) during operation, and performing the following adjustments independently or in combination based on the acquired temperature and / or humidity signals of the corresponding surface to be baked: Adjust the distance between the infrared heater (300) and the corresponding surface to be baked; Adjust the output radiation energy of the infrared heater (300).

8. The temperature closed-loop control method for electrode drying according to any one of claims 6 or 7, characterized in that, Based on the real-time acquired temperature and / or humidity signals, the following adjustments are performed independently or in combination: By adjusting the conveyor belt speed of the electrode (100), the surface temperature and / or humidity of the electrode (100) when it leaves the oven are kept within a preset range; Within the same baking section (200), by increasing or decreasing the number of activated infrared heaters (300), the surface temperature and / or humidity of the electrode (100) when it leaves the oven are kept within a preset range.

9. The temperature closed-loop control method for electrode drying according to claim 6, characterized in that, Collect state parameter signals inside the oven, which include at least temperature and / or humidity signals at multiple different locations distributed along the height direction inside the oven. Based on the collected state parameter signals inside the oven, perform the following adjustments independently or in combination: Adjust the distance between the infrared heater (300) and the corresponding surface to be baked; Adjust the output radiation energy of the infrared heater (300); Adjust the belt speed of the electrode (100).

10. The temperature closed-loop control method for electrode drying according to claim 9, characterized in that, Based on the collected state parameter signals inside the oven, active regulation is performed on the gas environment inside the oven. The active regulation includes performing any of the following methods independently or in combination: Cooling medium is introduced into the baking section (200) where the temperature is too high; Actively discharge the gas medium in the baking section (200) where the temperature is higher than the preset value; Actively discharge the gas medium in the baking section (200) where the humidity is higher than the preset value.

11. A baking apparatus for performing the temperature closed-loop control method for electrode drying according to any one of claims 1 to 10, comprising: An oven (500) has a baking zone inside. Both the inlet and outlet of the baking zone are equipped with infrared thermometers (600). The infrared thermometers (600) are used to detect the surface temperature of the electrode (100) when it enters and leaves the baking zone. A baking module is provided in the baking area. The baking module includes multiple baking sections (200) arranged along a first direction. The electrode (100) can pass through the baking section (200). At least one of the baking sections (200) is provided with an infrared thermometer (600). The infrared thermometer (600) is used to detect the surface temperature of the electrode (100) in the baking section (200).

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