Pole piece anti-cracking drying method and device and pole piece production line

Abstract

The invention provides a pole piece anti-cracking drying method and device and a pole piece production line, and relates to the technical field of battery manufacturing. The anti-cracking drying method for the pole piece is applied to the anti-cracking drying device for the pole piece, the anti-cracking drying device for the pole piece comprises a drying oven for baking the pole piece and a humidifier for humidifying the interior of the drying oven through atomization, and the anti-cracking drying method for the pole piece comprises the steps that the first dew point temperature in the drying oven is obtained; comparing the first dew point temperature with a target dew point temperature to obtain a first comparison result; and according to the first comparison result, atomization parameters of the humidifier are dynamically adjusted, so that the first dew point temperature is stabilized within the preset temperature range. On the basis, the first dew point temperature in the drying oven can be always kept near the target dew point temperature (namely within the preset temperature range), at the moment, the coating on the surface of the pole piece can be prevented from cracking, water drops can be prevented from damaging the structure of the coating on the surface of the pole piece, and therefore the production yield of the pole piece is effectively increased, and the quality of a battery can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery manufacturing, in particular to a tab anti-cracking drying method and device and a tab production line. BACKGROUND

[0002] A battery is a power supply component that can convert chemical energy into electrical energy, and the minimum energy conversion unit thereof is an electric core. The electric core is usually composed of a tab, a separator and two tabs. The tab has positive and negative, the positive tab and the negative tab are opposite, the separator is arranged between the positive tab and the negative tab, and the separator plays a role of isolation to prevent short circuit. The two tabs are respectively led out from the positive tab and the negative tab and exposed to the outside, and play a role of conducting current to realize connection with an external circuit. In the related art, when manufacturing the tab, the slurry (a mixture of an active material, a conductive agent, a binder and a solvent) coated on the current collector (aluminum foil for the positive tab and copper foil for the negative tab) needs to be baked in an oven, so as to form a slurry coating layer without water on the current collector. However, the oven is always heated and very dry (low dew point temperature), which makes the slurry on the current collector dry and form the slurry coating layer soon after entering the oven. Before the tab leaves the oven, the slurry coating layer will be directly baked in the oven, which causes the slurry coating layer to crack, and seriously affects the production yield of the tab. SUMMARY

[0003] The present application provides a tab anti-cracking drying method and device and a tab production line, aiming at solving the problem of low production yield of the tab due to the cracking of the slurry coating layer on the surface of the tab in the related art.

[0004] In order to solve the above-mentioned problems existing in the related art, the present application provides a tab anti-cracking drying method in the first aspect, which is applied to a tab anti-cracking drying device. The tab anti-cracking drying device includes an oven for baking the tab and a humidifier for humidifying the oven by atomization. Specifically, the tab anti-cracking drying method includes: obtaining a first dew point temperature in the oven; comparing the first dew point temperature with a target dew point temperature to obtain a first comparison result; and dynamically adjusting atomization parameters of the humidifier according to the first comparison result, so as to stabilize the first dew point temperature in a preset temperature range. Further, the step of dynamically adjusting the atomization parameters of the humidifier according to the first comparison result includes: when the first dew point temperature is less than the target dew point temperature, controlling the humidifier to increase the atomization amount and / or the flow of mist; and when the first dew point temperature is greater than the target dew point temperature, controlling the humidifier to decrease the atomization amount and / or the flow of mist.

[0005] In some implementations, the pole piece anti-cracking drying device includes an air duct through which the mist generated by the humidifier enters the oven, and the pole piece anti-cracking drying method includes: obtaining a second dew point temperature in the air duct; comparing the second dew point temperature with a target dew point temperature to obtain a second comparison result; and dynamically adjusting the atomization parameters of the humidifier according to the second comparison result to stabilize the second dew point temperature within a preset temperature range. The step of dynamically adjusting the atomization parameters of the humidifier according to the second comparison result includes: when the second dew point temperature is less than the target dew point temperature, controlling the humidifier to increase the atomization amount and / or the flow rate of the mist; and when the second dew point temperature is greater than the target dew point temperature, controlling the humidifier to decrease the atomization amount and / or the flow rate of the mist.

[0006] The second aspect of the present application provides a pole piece anti-cracking drying device for implementing the pole piece anti-cracking drying method provided in the first aspect of the present application. The pole piece anti-cracking drying device includes an oven, a humidifier, a controller, and a first dew point sensor. The first dew point sensor is arranged in the oven, the humidifier is connected to the oven, and the oven, the humidifier, and the first dew point sensor are respectively communicatively connected to the controller. Specifically, the oven is used to bake the pole piece to solidify the surface paste and form a coating layer; the humidifier is used to generate mist by atomization to humidify the inside of the oven; the first dew point sensor is used to detect the first dew point temperature in the oven in real time; and the controller is used to compare the first dew point temperature with a target dew point temperature to obtain a first comparison result, and dynamically adjust the atomization parameters of the humidifier according to the first comparison result, so as to stabilize the first dew point temperature within a preset temperature range.

[0007] In some implementations, the controller is specifically configured to: when the first dew point temperature is less than the target dew point temperature, control the humidifier to increase the atomization amount and / or the flow rate of the mist; and when the first dew point temperature is greater than the target dew point temperature, control the humidifier to decrease the atomization amount and / or the flow rate of the mist.

[0008] In some implementations, the pole piece anti-cracking drying device further comprises a circulating air system, the humidifier is connected to the oven through the circulating air system, and the circulating air system is used to collect the mist generated by the humidifier, the backflow air in the oven and the fresh air from the outside and deliver them into the oven to moisten the coating on the surface of the pole piece. In one or more of the implementations, the circulating air system comprises an air bellow, an air inlet pipe, an air outlet pipe, an upper air duct, a first circulating fan, a second circulating fan and a third circulating fan, the air bellow, the first circulating fan and the second circulating fan are arranged on the outer top wall of the oven, one end of the upper air duct is arranged on the outer side wall of the oven and is communicated with the oven, the other end of the upper air duct is communicated with the air bellow through the second circulating fan, the air bellow is communicated with the oven through the first circulating fan, the third circulating fan is arranged on the outer bottom wall of the oven, one end of the air inlet pipe is communicated with the oven through the third circulating fan, the other end of the air inlet pipe is connected to the humidifier, one end of the air outlet pipe is connected to the humidifier, the other end of the air outlet pipe is communicated with the air bellow, and the upper air duct has an upper air inlet for introducing fresh air from the outside. Specifically, the first circulating fan is used to send the backflow air in the oven into the air bellow; the third circulating fan is used to send the backflow air in the oven into the humidifier, and use the backflow air entering the humidifier to send the mist generated by the humidifier into the air bellow; and the second circulating fan is used to send the backflow air and the mist in the air bellow into the upper air duct to be collected with the fresh air entering through the upper air inlet and delivered into the oven.

[0009] In some implementations, the circulating air system further comprises a lower air duct, one end of the lower air duct is arranged on the outer side wall of the oven and is communicated with the oven, the other end of the lower air duct is connected to the third circulating fan, the lower air duct has a lower air inlet for introducing fresh air from the outside, and the third circulating fan is further used to send the backflow air in the oven into the lower air duct to be collected with the fresh air entering through the lower air inlet and delivered into the oven.

[0010] In some implementations, a second dew point sensor is arranged in the upper air duct and is communicated with the controller, the second dew point sensor is used to detect the second dew point temperature in the upper air duct in real time, the controller is further used to compare the second dew point temperature with the target dew point temperature to obtain a second comparison result, and dynamically adjust the atomization parameters of the humidifier according to the second comparison result to stabilize the second dew point temperature within the preset temperature range.

[0011] In some implementations, the controller is specifically used to: when the second dew point temperature is less than the target dew point temperature, control the humidifier to increase the atomization amount and / or the flow of the mist; and when the second dew point temperature is greater than the target dew point temperature, control the humidifier to decrease the atomization amount and / or the flow of the mist.

[0012] In some implementations, the circulating air system further comprises an air inlet adjusting valve and an air outlet adjusting valve, the air inlet adjusting valve and the air outlet adjusting valve are respectively communicated with the controller, the air inlet adjusting valve is connected between the air inlet pipe and the humidifier, and the air outlet adjusting valve is connected between the humidifier and the air outlet pipe.

[0013] The third aspect of the present application provides a pole piece production line, which comprises the pole piece anti-cracking drying device provided by the second aspect of the present application and a coating device arranged upstream of the pole piece anti-cracking drying device.

[0014] In some implementations, the pole piece production line comprises a plurality of pole piece anti-cracking drying devices, and the drying ovens of the plurality of pole piece anti-cracking drying devices are sequentially connected.

[0015] For the pole piece anti-cracking drying method provided by the first aspect of the present application, the first dew point temperature in the drying oven is acquired in real time, and the first dew point temperature is compared with the target dew point temperature to obtain a first comparison result, and then the atomization parameters (such as atomization amount, mist flow rate, etc.) of the humidifier (which humidifies the inside of the drying oven by atomization) are dynamically adjusted according to the first comparison result, with the purpose of stabilizing the first dew point temperature in the drying oven near the target dew point temperature (i.e. within the preset temperature range), so as to avoid both the cracking of the coating on the surface of the pole piece and the damage of the structure of the coating on the surface of the pole piece by water droplets, thereby effectively improving the production yield of the pole piece and the quality of the battery.

[0016] For the pole piece anti-cracking drying device provided by the second aspect of the present application, it is composed of a drying oven, a humidifier, a controller and a first dew point sensor, the first dew point sensor is arranged in the drying oven, the humidifier is connected to the drying oven, and the drying oven, the humidifier and the first dew point sensor are respectively communicatively connected to the controller. In actual application, the coating device is used to coat slurry on the surface of the pole piece, and then the pole piece is sent into the drying oven for baking, so as to finally solidify the slurry on the surface of the pole piece to form a coating. During this process, the controller controls the humidifier to humidify the inside of the drying oven to wet the coating on the surface of the pole piece to avoid its cracking. The first dew point sensor can detect the first dew point temperature in the drying oven in real time and transmit it to the controller. The controller compares the first dew point temperature with the target dew point temperature and dynamically adjusts the atomization parameters (such as atomization amount, mist flow rate, etc.) of the humidifier according to the comparison result, with the purpose of stabilizing the first dew point temperature in the drying oven near the target dew point temperature (i.e. within the preset temperature range), so as to avoid both the cracking of the coating on the surface of the pole piece and the damage of the structure of the coating on the surface of the pole piece by water droplets, thereby effectively improving the production yield of the pole piece.

[0017] For the pole piece production line provided by the third aspect of the present application, it comprises the pole piece anti-cracking drying device provided by the second aspect of the present application, and therefore has all the advantages of the device. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the related art or the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the related art or the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application and not all the embodiments. Those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0019] Figure 1 The first structural schematic diagram of the pole piece anti-cracking drying device provided by the embodiments of the present application;

[0020] Figure 2 The second structural schematic diagram of the pole piece anti-cracking drying device provided by the embodiments of the present application;

[0021] Figure 3 The third structural schematic diagram of the pole piece anti-cracking drying device provided by the embodiments of the present application;

[0022] Figure 4 The structural schematic diagram of the pole piece production line provided by the embodiments of the present application;

[0023] Figure 5 The flowchart of the pole piece anti-cracking drying method provided by the embodiments of the present application.

[0024] The marks in the above various drawings respectively represent:

[0025] 1-oven, 2-humidifier, 3-circulating air system, 30-air bellow, 31-first circulating fan, 32-second circulating fan, 33-third circulating fan, 34-upper air duct, 341-upper air outlet, 35-lower air duct, 351-lower air outlet, 36-inlet air pipe, 37-outlet air pipe, 38-inlet air regulating valve, 39-outlet air regulating valve, 4-rack. DETAILED DESCRIPTION

[0026] In the related art, when manufacturing the pole piece of the battery, the oven is used to bake the slurry (a mixture of active material, conductive agent, binder and solvent) coated on the base (also known as current collector, the positive pole piece is aluminum foil and the negative pole piece is copper foil) so as to form a slurry coating layer without water on the current collector. However, the oven is always heated and very dry (low dew point temperature), which makes the slurry on the current collector complete drying and form a slurry coating layer soon after entering the oven. Before the pole piece leaves the oven, the slurry coating layer will be directly baked by the oven, which easily causes the slurry coating layer to crack, seriously affecting the production yield of the pole piece. In view of this, the embodiments of the present application propose a pole piece anti-cracking drying device and method, a pole piece production line, to solve the above-mentioned drawbacks existing in the related art.

[0027] In order to make the purposes, technical solutions and advantages of the present application more obvious and easy to understand, the present application will be described clearly and completely below in combination with the embodiments of the present application and the corresponding drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. It should be understood that the embodiments of the present application described below are only used to explain the present application and do not limit the present application, that is, all other embodiments obtained by those skilled in the art without creative labor based on the various embodiments of the present application belong to the scope of protection of the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0028] Please refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 is a first structural schematic diagram of the pole piece anti-cracking drying device, Figure 2 is a second structural schematic diagram of the pole piece anti-cracking drying device, Figure 3 is a third structural schematic diagram of the pole piece anti-cracking drying device. The present embodiment provides a pole piece anti-cracking drying device, which comprises an oven 1, a rack 4, a humidifier 2, a controller (not shown in the figure), a circulating air system 3 and a first dew point sensor (not shown in the figure), the oven 1 and the humidifier 2 are both arranged on the rack 4, the first dew point sensor is arranged in the oven 1, the humidifier 2 is connected to the oven 1 through the circulating air system 3, and the oven 1, the humidifier 2, the circulating air system 3 and the first dew point sensor are respectively communicatively connected to the controller, that is, the working of the oven 1, the humidifier 2, the circulating air system 3 and the first dew point sensor is all under the control of the controller.

[0029] It should be noted that the controller can adopt any device with control and data processing and analysis functions commonly used in the art, such as small computers, microcontrollers such as single-chip microcontrollers, and industrial control computers (IPC), programmable logic controllers (PLC), and distributed control systems (DCS), etc. The specific selection can be based on actual needs, and the present embodiment does not make a unique limitation in this regard. Exemplarily, the controller of the present embodiment adopts a PLC control cabinet. It should also be noted that the structure and working principle of the oven 1 are relatively mature technologies in the art, and the present embodiment does not make a detailed description in this regard. Exemplarily, the oven 1 includes a cabinet, a heating system, a temperature control system, and auxiliary structures. The cabinet is composed of an outer shell, an inner container, and a thermal insulation layer. The outer shell serves a protective function. The inner container provides space for the baking of the pole piece. The thermal insulation layer reduces heat loss. The core of the heating system is a heating element, such as a common electric heating tube (stainless steel material). It can also be equipped with a burner (gas / oil type). The temperature control system is composed of a temperature sensor (thermocouple / PT100), a temperature controller, and an actuator, which is responsible for detecting, setting, and adjusting the temperature in the cabinet. The auxiliary structures include, for example, a door (equipped with a sealing strip), a safety device (over-temperature protection, overload protection), etc.

[0030] In the present embodiment, the oven 1 is used to bake the pole piece, thereby curing the paste on the surface of the pole piece and forming a coating layer. The humidifier 2 is used to generate mist by atomization. The circulating air system 3 is used to collect the mist, the backflow air in the oven 1, and the fresh air from the outside and deliver them into the oven 1 to moisten the coating layer on the surface of the pole piece. The first dew point sensor is used to detect the first dew point temperature in the oven 1 in real time. The controller is used to compare the first dew point temperature with the target dew point temperature to obtain a first comparison result, and dynamically adjust the atomization parameters of the humidifier 2 according to the first comparison result, so as to stabilize the first dew point temperature within a preset temperature range, and the target dew point temperature is located within the preset temperature range (for example, the median of the preset temperature range is the target dew point temperature). Specifically, the humidifier 2 can adopt any device commonly used in the art and having a humidifying function, such as an ultrasonic atomizer. Compared with conventional water mist (water droplets), the ultrasonic atomizer can form smaller and more uniform mist particles, which have less impact on the coating layer on the surface of the pole piece, only moistening the surface of the coating layer to avoid cracking, while the water mist (water droplets) can penetrate the coating layer on the surface of the pole piece, resulting in water content in the coating layer, thereby damaging the structure of the coating layer and affecting the quality of the pole piece, and the quality of the battery will also decrease.

[0031] That is to say, in actual application, the slurry is first coated on the surface of the pole piece by the coating device, and then the pole piece is sent into the oven 1 for baking, and finally the slurry on the surface of the pole piece is solidified to form a coating. In this process, the controller not only controls the humidifier 2 to generate mist by atomization, but also controls the circulating air system 3 to collect the mist generated by the humidifier 2, the backflow air in the oven 1 and the fresh air from the outside to obtain a mixed airflow for humidification, and then delivers the mixed airflow for humidification into the oven 1 to act on the coating on the surface of the pole piece. The mixed airflow for humidification can humidify the coating on the surface of the pole piece to avoid cracking of the coating on the surface of the pole piece. The first dew point sensor can detect the first dew point temperature in the oven 1 in real time and transmit it to the controller. The controller compares the first dew point temperature with the target dew point temperature, and dynamically adjusts the atomization parameters (such as atomization amount, mist flow rate, etc.) of the humidifier 2 according to the comparison result. The purpose is to stabilize the first dew point temperature in the oven 1 near the target dew point temperature (i.e. within the preset temperature range), which can not only avoid cracking of the coating on the surface of the pole piece, but also avoid water droplets damaging the structure of the coating on the surface of the pole piece, thereby effectively improving the production yield of the pole piece. It should be noted that the first time the pole piece anti-cracking drying device in this embodiment is started, the inlet air is only fresh air from the outside. After that, as the pole piece anti-cracking drying device operates, the inlet air includes backflow air in the oven 1, fresh air from the outside and mist generated by the humidifier 2. As the name implies, backflow air refers to air flow from the oven 1. Therefore, as the pole piece anti-cracking drying device operates, at least part of the fresh air and mist entering the oven 1 also act as backflow air. It should be further noted that the atomization amount of the ultrasonic atomizer is 0-50 L / H, which can be adjusted by adjusting the number of opened atomization plates inside the ultrasonic atomizer.

[0032] In this embodiment, when the first dew point temperature in the oven 1 is less than the target dew point temperature, it indicates that the oven 1 is too dry. The controller will control the humidifier 2 to increase the atomization amount and / or the flow rate of the mist, thereby increasing the humidity of the mixed airflow for humidification and raising the first dew point temperature in the oven 1 to the vicinity of the target dew point temperature (i.e. within the preset temperature range), thereby improving the dryness in the oven 1 and avoiding cracking of the coating on the pole piece. When the first dew point temperature in the oven 1 is greater than the target dew point temperature, it indicates that the oven 1 is too humid. The controller will control the humidifier 2 to reduce the atomization amount and / or the flow rate of the mist, thereby reducing the humidity of the mixed airflow for humidification and lowering the first dew point temperature in the oven 1 to the vicinity of the target dew point temperature (i.e. within the preset temperature range), thereby improving the humidity in the oven 1 and avoiding the slurry on the surface of the pole piece not being dried (i.e. the slurry not being solidified into a coating) when the pole piece leaves the oven 1, and also avoiding water droplets damaging the structure of the coating on the surface of the pole piece in a humid environment. It should be noted that the preset temperature range is the target dew point temperature ± 5℃. For example, when the target dew point temperature is 30℃, the preset temperature range is 25-35℃.

[0033] From the above, through the cooperation between the controller, the humidifier 2, the circulating air system 3 and the first dew point sensor, the first dew point temperature in the oven 1 can be kept near the target dew point temperature, which not only avoids the cracking of the coating on the surface of the pole piece, but also avoids the water droplets from damaging the structure of the coating on the surface of the pole piece, thereby effectively improving the production yield of the pole piece and the quality of the battery.

[0034] In some embodiments, the circulating air system 3 comprises a wind box 30, an air inlet pipe 36, an air outlet pipe 37, an upper air duct 34, a first circulating fan 31, a second circulating fan 32 and a third circulating fan 33, the first circulating fan 31, the second circulating fan 32 and the wind box 30 are arranged on the outer top wall of the oven 1, one end of the upper air duct 34 is arranged on the outer side wall of the oven 1 and communicates with the oven 1, the other end of the upper air duct 34 communicates with the wind box 30 through the second circulating fan 32, the wind box 30 communicates with the oven 1 through the first circulating fan 31, the third circulating fan 33 is arranged on the outer bottom wall of the oven 1, one end of the air inlet pipe 36 communicates with the oven 1 through the third circulating fan 33, the other end of the air inlet pipe 36 is connected to the humidifier 2, one end of the air outlet pipe 37 is connected to the humidifier 2, the other end of the air outlet pipe 37 communicates with the wind box 30, and the upper air duct 34 has at least one upper air inlet 341, each upper air inlet 341 is used to introduce fresh air from the outside.

[0035] Specifically, the first circulating fan 31 can send the backflow air in the oven 1 into the wind box 30; the third circulating fan 33 can send the backflow air in the oven 1 into the humidifier 2, and use the backflow air entering the humidifier 2 to send the mist generated by the humidifier 2 into the wind box 30; the second circulating fan 32 can send the backflow air and the mist in the wind box 30 into the upper air duct 34, and combine with the fresh air entering through the upper air inlet 341 in the upper air duct 34 to form a mixed air flow for humidification, which will enter the oven 1 through the upper air duct 34 under the pushing of the second circulating fan 32 and act on the coating on the surface of the pole piece.

[0036] It can be understood that when the first circulating fan 31 sends the backflow air in the oven 1 into the wind box 30 and the third circulating fan 33 sends the backflow air in the oven 1 into the humidifier 2, a negative pressure is formed in the oven 1, causing the fresh air from the outside to enter the upper air duct 34 through the upper air inlet 341; in addition, the third circulating fan 33 can send the backflow air in the oven 1 into the wind box 30 through the air inlet pipe 36, the humidifier 2 and the air outlet pipe 37 in sequence, and the backflow air in the oven 1 will flow into the wind box 30 with the mist generated by the humidifier 2 when passing through the humidifier 2, that is, the purpose of the third circulating fan 33 sending the backflow air in the oven 1 into the wind box 30 is to provide power for the flow of the mist generated by the humidifier 2 into the wind box 30.

[0037] Further, the circulating air system 3 comprises, in addition to the structure given above, a lower air duct 35, one end of the lower air duct 35 being arranged on the outer side wall of the oven 1 and being communicated with the oven 1, the other end of the lower air duct 35 being connected to the third circulating air fan 33, the lower air duct 35 having at least one lower air inlet 351, each lower air inlet 351 being used to introduce fresh air from outside. Based on this, in actual application, the third circulating air fan 33 will not only send the backflow air in the oven 1 to the humidifier 2, but also send the backflow air in the oven 1 to the lower air duct 35, so as to be collected with the fresh air entering through the lower air inlet 351 in the lower air duct 35 and be transported into the oven 1. It can be understood that the circulating air system 3 of the present application realizes the closed-loop flow of air flow through the cooperation between the air bellow 30, the air inlet pipe 36, the air outlet pipe 37, the upper air duct 34, the lower air duct 35, the first circulating air fan 31, the second circulating air fan 32 and the third circulating air fan 33, and guarantees the effect of baking the pole piece and humidifying the surface coating of the pole piece. In addition, it should be noted that, although one end of the upper air duct 34 and one end of the lower air duct 35 are arranged on the outer side wall of the oven 1, the upper air duct 34 is located at the upper part of the oven 1, and the lower air duct 35 is located at the lower part of the oven 1, i.e. the upper air duct 34 and the lower air duct 35 are located above and below the pole piece in the oven 1 respectively.

[0038] Further, the circulating air system 3 comprises, in addition to the structure given above, an air inlet adjusting valve 38 and an air outlet adjusting valve 39, the air inlet adjusting valve 38 and the air outlet adjusting valve 39 being respectively connected in communication with the controller, the air inlet adjusting valve 38 being connected between the air inlet pipe 36 and the humidifier 2, and the air outlet adjusting valve 39 being connected between the humidifier 2 and the air outlet pipe 37. In actual application, the controller can control the valve core of the air inlet adjusting valve 38 and / or the air outlet adjusting valve 39 to act, so as to adjust the flow of the mist gas output by the humidifier 2, and further regulate the first dew point temperature in the oven 1. It should be noted that the air inlet adjusting valve 38 and the air outlet adjusting valve 39 can all adopt any device commonly used in the art and having the flow adjusting function, such as an electric air valve, and the flow of the mist gas output by the humidifier 2 can be adjusted by adjusting the angle of the shielding plate in the electric air valve.

[0039] In some embodiments, a second dew point sensor is arranged in the upper air duct 34 of the circulating air system 3 and is communicatively connected to the controller. The second dew point sensor can detect the second dew point temperature in the upper air duct 34 (also the second dew point temperature of the humidified mixed air flow) in real time. The second dew point temperature of the humidified mixed air flow also needs to match the target dew point temperature in the oven 1. Therefore, the controller also compares the second dew point temperature with the target dew point temperature to obtain a second comparison result, and dynamically adjusts the atomization parameters of the humidifier 2 according to the second comparison result, so as to stabilize the second dew point temperature in the preset temperature range. Specifically, when the second dew point temperature is less than the target dew point temperature, the controller controls the humidifier 2 to increase the atomization amount and / or the flow rate of the mist; when the second dew point temperature is greater than the target dew point temperature, the controller controls the humidifier 2 to decrease the atomization amount and / or the flow rate of the mist.

[0040] Please refer to Figure 4 , Figure 4 is a structural schematic diagram of the pole piece production line. The pole piece production line provided in the embodiment includes a coating device and the pole piece anti-cracking drying device described above, and the coating device is arranged upstream of the pole piece anti-cracking drying device. Specifically, the slurry is coated on the surface of the pole piece through the coating device, and then the pole piece is sent into the oven 1 of the pole piece anti-cracking drying device for baking, so that the slurry on the surface of the pole piece is finally solidified to form a coating. The pole piece anti-cracking drying device not only can avoid the cracking of the coating on the surface of the pole piece during the baking process, but also can avoid the water droplets from damaging the structure of the coating on the surface of the pole piece. Therefore, the production yield of the pole piece is higher than that of the conventional scheme, and the quality of the battery manufactured by the pole piece is also better.

[0041] In actual application, in order to meet the demand of high-speed production, the pole piece production line is very long, that is, the pole piece production line includes multiple pole piece anti-cracking drying devices, the drying ovens 1 of the multiple pole piece anti-cracking drying devices are sequentially connected, the pole pieces will sequentially pass through the drying ovens 1 of the multiple pole piece anti-cracking drying devices, and finally the solidification of the surface slurry of the pole pieces is realized, so that the coating is formed on the surface of the pole pieces. Based on this, in order to avoid the surface coating of the pole pieces from cracking due to long-time baking when the pole pieces are transported on the whole production line, the first dew point temperature in the drying oven 1 is controlled by a staged control strategy in this embodiment. Specifically, the production line is divided into multiple sections along the transport direction of the pole pieces, and each section includes multiple pole piece anti-cracking drying devices that are sequentially connected; for example, the production line is divided into a preliminary section, an intermediate section and a tail section along the transport direction of the pole pieces, the pole pieces just enter the baking in the preliminary section, the surface slurry of the pole pieces has not been solidified and is very wet, so it is not necessary to humidify the surface slurry by using the mist generated by the humidifier 2; the surface slurry of the pole pieces is in a gradually drying or drying state in the intermediate section, and the mist generated by the humidifier 2 is used to humidify the surface slurry, and the first target dew point temperature is set; even if the surface slurry of the pole pieces is in a drying state to form a coating, the coating will not crack under the humidification of the mist; the tail section can also be humidified by using the mist generated by the humidifier 2, and the second target dew point temperature (which is less than the first target dew point temperature) is set, the surface slurry of the pole pieces is in a drying state to form a coating, and the coating will not crack under the humidification of the mist, and the surface of the pole pieces remains dry when the pole pieces come out of the last drying oven 1. In addition, it should be noted that the intermediate section is not limited to using the same target dew point temperature, and multiple target dew point temperatures that decrease along the transport direction of the pole pieces can be set according to the length of the production line, and the target dew point temperature of the tail section is the lowest or even zero.

[0042] Please refer to Figure 5 , Figure 5 is a flowchart of a pole piece anti-cracking baking method. The pole piece anti-cracking baking method provided in this embodiment is realized based on the structure of the pole piece anti-cracking baking device described in the foregoing, is applied to the controller of the pole piece anti-cracking baking device, and includes steps 501 to 503 (abbreviated as S501 to S503), that is: S501, obtaining the first dew point temperature in the drying oven; S502, comparing the first dew point temperature with the target dew point temperature to obtain a first comparison result; and S503, dynamically adjusting the atomization parameters of the humidifier according to the first comparison result, so as to stabilize the first dew point temperature near the target dew point temperature (that is, within the preset temperature range). It should be noted that the details of the pole piece anti-cracking baking method (such as dynamically adjusting the atomization parameters of the humidifier according to the second comparison result) are described in the foregoing related description of the pole piece anti-cracking baking device, and will not be described herein again.

[0043] The above embodiments are only preferred implementations of the present application, and are not the only limitations of the polar piece anti-cracking drying device and related methods and polar piece production lines. Based on the above embodiments, a person skilled in the art can make flexible settings according to actual application scenarios. It can be understood that by implementing the above embodiments of the present application, the polar piece anti-cracking drying device is formed by the oven 1, the humidifier 2, the controller, the circulating air system 3 and the first dew point sensor. The first dew point sensor is arranged in the oven 1. The humidifier 2 is connected to the oven 1 through the circulating air system 3. The oven 1, the humidifier 2, the circulating air system 3 and the first dew point sensor are respectively communicatively connected to the controller. In actual application, the slurry is first coated on the surface of the polar piece by using the coating device, and then the polar piece is sent into the oven 1 for baking, so that the slurry on the surface of the polar piece is solidified to form a coating. During this process, the controller not only controls the humidifier 2 to generate mist by atomization, but also controls the circulating air system 3 to collect the mist, the backflow air in the oven 1 and the fresh air from the outside and deliver them into the oven 1 to act on the coating on the surface of the polar piece, so as to humidify the coating on the surface of the polar piece to avoid its cracking. The first dew point sensor can detect the first dew point temperature in the oven 1 in real time. The controller compares the first dew point temperature with the target dew point temperature, and dynamically adjusts the atomization parameters (such as atomization amount, mist flow rate, etc.) of the humidifier 2 according to the comparison result. The purpose is to stabilize the first dew point temperature in the oven 1 near the target dew point temperature (i.e. within the preset temperature range), which can not only avoid the cracking of the coating on the surface of the polar piece, but also avoid the water droplets from damaging the structure of the coating on the surface of the polar piece, thereby effectively improving the production yield of the polar piece.

[0044] It should be noted that the embodiments shown in the foregoing of the present application are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be referred to each other. It should also be noted that the relationship terms such as first, second and the like in the description of the present application are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply such actual relationship or order between the entities or operations. Further, the terms "include", "contain" or any other corresponding variant are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes these elements, but also can include other elements not explicitly listed, or can include elements inherent to the process, method, article or device; and without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device.

[0045] Moreover, those skilled in the art will appreciate that the application is practiced with neither of the described specific embodiments, but that the instant application is realized and / or is in possession of more general embodiments that follow in the broader scope of the application. Thus, the application is not to be limited to any specifically recited embodiments, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for drying electrodes to prevent cracking, characterized in that, The electrode anti-cracking drying device is used in a device for drying electrodes, which includes an oven (1) for baking electrodes and a humidifier (2) for humidifying the oven (1) by atomization. The electrode anti-cracking drying method includes: Obtain the first dew point temperature inside the oven (1); The first comparison result is obtained by comparing the first dew point temperature with the target dew point temperature; The atomization parameters of the humidifier (2) are dynamically adjusted according to the first comparison result to stabilize the first dew point temperature within the preset temperature range.

2. The electrode drying method for preventing cracking according to claim 1, characterized in that, The step of dynamically adjusting the atomization parameters of the humidifier (2) based on the first comparison result includes: When the first dew point temperature is lower than the target dew point temperature, the humidifier (2) is controlled to increase the atomization amount and / or the flow rate of the mist; When the first dew point temperature is greater than the target dew point temperature, the humidifier (2) is controlled to reduce the amount of atomization and / or the flow rate of mist.

3. The electrode drying method for preventing cracking according to claim 1, characterized in that, The electrode anti-cracking drying device further includes an air duct for the mist generated by the humidifier (2) to enter the drying oven (1), and the electrode anti-cracking drying method further includes: Obtain the second dew point temperature within the air duct; A second comparison result is obtained by comparing the second dew point temperature with the target dew point temperature; The atomization parameters of the humidifier (2) are dynamically adjusted according to the second comparison result to stabilize the second dew point temperature within the preset temperature range.

4. The electrode drying method for preventing cracking according to claim 3, characterized in that, The step of dynamically adjusting the atomization parameters of the humidifier (2) based on the second comparison result includes: When the second dew point temperature is lower than the target dew point temperature, the humidifier (2) is controlled to increase the atomization amount and / or the flow rate of the mist; When the second dew point temperature is greater than the target dew point temperature, the humidifier (2) is controlled to reduce the amount of atomization and / or the flow rate of the mist.

5. A device for drying electrodes to prevent cracking, characterized in that, The electrode anti-cracking drying method according to any one of claims 1 to 4 includes an oven (1), a humidifier (2), a controller, and a first dew point sensor. The first dew point sensor is disposed inside the oven (1), the humidifier (2) is connected to the oven (1), and the oven (1), the humidifier (2), and the first dew point sensor are respectively communicatively connected to the controller. The oven (1) is used to bake the electrode sheets; The humidifier (2) is used to humidify the interior of the oven (1) by atomization; The first dew point sensor is used to detect the first dew point temperature inside the oven (1) in real time; The controller is used to compare the first dew point temperature with the target dew point temperature to obtain a first comparison result, and dynamically adjust the atomization parameters of the humidifier (2) according to the first comparison result, so as to stabilize the first dew point temperature within a preset temperature range.

6. The electrode anti-cracking drying device according to claim 5, characterized in that, The controller is specifically used to: when the first dew point temperature is less than the target dew point temperature, control the humidifier (2) to increase the atomization amount and / or the flow rate of the mist; when the first dew point temperature is greater than the target dew point temperature, control the humidifier (2) to decrease the atomization amount and / or the flow rate of the mist.

7. The electrode anti-cracking drying device according to claim 5, characterized in that, It also includes a circulating air system (3), through which the humidifier (2) is connected to the oven (1). The circulating air system (3) is used to collect the mist generated by the humidifier (2), the return air in the oven (1) and the fresh air from the outside and deliver them to the oven (1). The circulating air system (3) includes a wind box (30), an air inlet pipe (36), an air outlet pipe (37), an upper air duct (34), a first circulating fan (31), a second circulating fan (32), and a third circulating fan (33). The wind box (30), the first circulating fan (31), and the second circulating fan (32) are all located on the outer top wall of the oven (1). One end of the upper air duct (34) is located on the outer side wall of the oven (1) and connected to the oven (1), while the other end is connected to the wind box (30) via the second circulating fan (32). The air box (30) is connected to the oven (1) through the first circulating fan (31). The third circulating fan (33) is located on the outer bottom wall of the oven (1). One end of the air inlet pipe (36) is connected to the oven (1) through the third circulating fan (33), and the other end is connected to the humidifier (2). One end of the air outlet pipe (37) is connected to the humidifier (2), and the other end is connected to the air box (30). The upper air duct (34) has an upper air outlet (341) for introducing fresh air from the outside. The first circulating fan (31) is used to send the return air in the oven (1) into the air box (30). The third circulating fan (33) is used to send the return air in the oven (1) into the humidifier (2), and use the return air entering the humidifier (2) to send the mist generated by the humidifier (2) into the air box (30). The second circulating fan (32) is used to send the return air and mist in the air box (30) into the upper air duct (34) to be combined with the fresh air entering through the upper air inlet (341) and delivered to the oven (1).

8. The electrode anti-cracking drying device according to claim 7, characterized in that, The circulating air system (3) also includes a downdraft duct (35), one end of which is located on the outer wall of the oven (1) and connected to the oven (1), and the other end is connected to the third circulating fan (33). The downdraft duct (35) has a downdraft opening (351) for introducing fresh air from the outside. The third circulating fan (33) is also used to: send the return air in the oven (1) into the downdraft duct (35) to combine with the fresh air entering through the downdraft opening (351) and deliver it into the oven (1).

9. The electrode anti-cracking drying device according to claim 7, characterized in that, The upper air duct (34) is equipped with a second dew point sensor that is connected to the controller. The second dew point sensor is used to detect the second dew point temperature in the upper air duct (34) in real time. The controller is also used to compare the second dew point temperature with the target dew point temperature to obtain a second comparison result, and dynamically adjust the atomization parameters of the humidifier (2) according to the second comparison result to stabilize the second dew point temperature within the preset temperature range.

10. The electrode anti-cracking drying device according to claim 9, characterized in that, The controller is specifically used to: when the second dew point temperature is less than the target dew point temperature, control the humidifier (2) to increase the atomization amount and / or the flow rate of the mist; when the second dew point temperature is greater than the target dew point temperature, control the humidifier (2) to decrease the atomization amount and / or the flow rate of the mist.

11. The electrode anti-cracking drying device according to claim 7, characterized in that, The circulating air system (3) further includes an air inlet regulating valve (38) and an air outlet regulating valve (39). The air inlet regulating valve (38) and the air outlet regulating valve (39) are respectively connected to the controller. The air inlet regulating valve (38) is connected between the air inlet pipe (36) and the humidifier (2), and the air outlet regulating valve (39) is connected between the humidifier (2) and the air outlet pipe (37).

12. An electrode production line, characterized in that, The device includes the electrode anti-cracking drying apparatus according to any one of claims 5 to 11 and the coating apparatus disposed upstream of the electrode anti-cracking drying apparatus.

13. The electrode production line according to claim 12, characterized in that, The electrode anti-cracking drying device includes multiple units, and the ovens (1) of the multiple electrode anti-cracking drying devices are connected in sequence.

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