Battery pole piece production system and battery pole piece drying method

Abstract

The invention provides a battery pole piece production system and a battery pole piece drying method.The battery pole piece production system comprises a coating back roller, a coating die head, a first heating device and a second heating device which are arranged in the current collector conveying direction; the coating back roller and the coating die head are oppositely arranged, the coating back roller is used for supporting and transmitting a current collector, and the coating die head is used for extruding slurry on the current collector; the first heating device is used for heating the ceramic slurry on the current collector for the first time, and the second heating device is used for heating the ceramic slurry and the active material slurry on the current collector for the second time. During primary heating, the first heating device only heats and dries the ceramic slurry, so that the center position of the ceramic slurry is quickly solidified, the unsolidified ceramic slurry is difficult to flow to one side of the active material slurry, and the risk that the two kinds of slurry are mixed at the interface of the two kinds of slurry due to the fact that the ceramic slurry flows to the active material slurry can be effectively reduced; and thus, the problem of ceramic virtual edges is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery processing and manufacturing, and particularly relates to a battery pole piece production system and a battery pole piece drying method. Background Art

[0002] Lithium-ion batteries have been widely used in many fields due to their advantages such as high energy density, small size, long service life and low self-discharge.

[0003] Coating is an essential and key process in the production process of lithium-ion batteries. Ceramics are widely used as insulating materials in the manufacture of positive electrode coated pole pieces. Ceramic slurry and active material slurry are coated on the surface of the current collector. However, at the interface between the two slurries, the two slurries blend into each other due to internal and external factors such as different densities of the slurries, mechanical vibration, and hot air blowing, causing blurred boundaries and producing ceramic virtual edges.

[0004] Ceramic virtual edges will lead to a decrease in insulation performance, and imbalance in battery safety performance and battery pack consistency. Summary of the Invention

[0005] The embodiments of the present invention provide a battery pole piece production system and a battery pole piece drying method to solve the problem of liquid ceramic diffusing toward solid slurry to form virtual edges during pole piece drying.

[0006] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0007] In a first aspect, an embodiment of the present invention provides a battery pole piece production system, comprising: a coating back roller arranged along a current collector transmission direction, a coating die head, a first heating device and a second heating device;

[0008] The coating back roller and the coating die head are arranged opposite to each other, the coating back roller is used to support and transport the current collector, and the coating die head is used to squeeze the slurry onto the current collector;

[0009] The first heating device is used to heat the ceramic slurry on the current collector for the first time, and the second heating device is used to heat the ceramic slurry and active material slurry on the current collector for the second time.

[0010] Optionally, the first heating device further includes an isolation cover and a heating head; the isolation cover is provided on the heating head; and the heating head is used to perform a first heating on the ceramic slurry on the current collector.

[0011] Optionally, the first heating device further includes a slider and a slide rail;

[0012] The slider is movably connected to the slide rail, and the slider is fixedly connected to the heating head.

[0013] In a second aspect, an embodiment of the present invention provides a method for drying a battery electrode, comprising:

[0014] The current collector coated with the slurry is transported to a first heating device; the slurry includes a ceramic slurry and an active material slurry; the ceramic slurry and the active material slurry are adjacently arranged on the same side of the current collector;

[0015] controlling the first heating device to heat the ceramic slurry on the current collector for a first time;

[0016] The current collector is transported to a second heating device, and the second heating device is controlled to heat the ceramic slurry and the active material slurry on the current collector for a second time.

[0017] Optionally, within the plane where the current collector is located, there are a first direction and a second direction perpendicular to each other, the width direction of the slurry is the first direction, the current collector transmission direction is the second direction, and along the first direction, the region where the ceramic slurry is located includes a first region and a second region, and the first region is located between the two second regions;

[0018] The step of controlling the first heating device to heat the ceramic slurry on the current collector for the first time includes:

[0019] The first heating device is controlled to heat the first area.

[0020] Optionally, before controlling the first heating device to heat the first area, the method further includes:

[0021] Continuously acquiring a plurality of thickness values ​​of the ceramic slurry along a third direction from the boundary to the center of the ceramic slurry at a preset interval by a detector; wherein the third direction is the thickness direction of the slurry;

[0022] The first region and the second region are determined according to the plurality of thickness values, wherein the thickness of the first region is greater than the thickness of the second region.

[0023] Optionally, the step of determining the first region and the second region according to the multiple thickness values, wherein the thickness of the first region is greater than the thickness of the second region, includes:

[0024] The first region and the second region are determined by taking the target position corresponding to the first detected thickness value among the multiple thickness values ​​as the target thickness value; the target thickness value is the thickness value of the center position of the ceramic slurry along the first direction in the third direction;

[0025] Alternatively, when the thickness values ​​detected multiple times are the same, the first area and the second area are determined based on the position corresponding to the thickness value detected for the first time among the multiple times of the same thickness values ​​detected.

[0026] Optionally, the first heating device includes a heating head, and the step of controlling the first heating device to heat the first area includes:

[0027] The heating head is controlled to face the first area, and the orthographic projection of the heating head on the first area is located within the range of the first area.

[0028] Optionally, along the first direction, the ceramic slurry has a center of symmetry, and the center of symmetry is located in the first region. In the step of controlling the heating head to face the first region, the orthographic projection of the heating head in the first region is controlled to be located at the center of symmetry;

[0029] And / or, the first heating device further comprises an isolation cover; the isolation cover is provided on the heating head; and during the first heating process, the orthographic projection of the isolation cover on the first area is controlled to be within the range of the first area.

[0030] Optionally, the width of the first region along the first direction is a, the width of the heating head in the first direction is c, and 0.5a≤c <a;

[0031] And / or, the heating temperature of the first heating is 80-140°C, and the heating time is 0.2-0.8 seconds. In an embodiment of the present application, the battery electrode production system performs primary and secondary heating of the slurry on the electrode current collector by sequentially setting a first heating device and a second heating device, and step-by-step drying provides a temperature and humidity controllable drying environment with less external interference for the electrode drying. During the first heating, the first heating device only heats and dries the ceramic slurry, causing the center of the ceramic slurry to solidify rapidly, thereby making it difficult for the unsolidified ceramic slurry to flow to the side of the active material slurry, which can effectively reduce the risk of the ceramic slurry flowing to the active material slurry and causing the two slurries to mix at the interface of the two slurries, thereby reducing the problem of ceramic virtual edges. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 This is a schematic diagram of a battery electrode production system provided in an embodiment of the present application;

[0034] Figure 2This is a schematic diagram of a first area and a second area during primary heating of a battery electrode production system provided in an embodiment of the present application;

[0035] Figure 3 This is another schematic diagram of the first area and the second area during primary heating of a battery electrode production system provided by an embodiment of the present application;

[0036] Figure 4 is a schematic diagram of the thickness relationship between the first region and the second region in an embodiment of the present application;

[0037] Figure 5 is a schematic diagram of a first heating device in an embodiment of the present application;

[0038] Figure 6 is another schematic diagram of the first heating device in an embodiment of the present application;

[0039] Figure 7 Schematic diagram of the isolation cover in the embodiment of the present application;

[0040] Figure 8 This is a flow chart of a method for drying a battery electrode in an embodiment of the present application;

[0041] Figure 9 This is another flow chart of a battery electrode drying method in an embodiment of the present application.

[0042] Description of reference numerals:

[0043] 10. First heating device, 101. Isolation cover, 102. Heating head, 103. Slider, 104. Slide rail, 20. Second heating device, 30. Current collector, 40. Slurry, 401. Ceramic slurry, 4011. First region, 4012. Second region, 402. Active material slurry, 50. Coating back roller, 60. Coating die head, Z, first direction, X, second direction, Y, third direction. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] The terms "first," "second," and the like in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present invention can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0046] The battery electrode drying device provided by the embodiment of the present invention is described in detail below with reference to the accompanying drawings through specific embodiments and application scenarios.

[0047] Coating is an essential and critical process in the production of lithium-ion batteries. Ceramics, as insulating materials, are widely used in the manufacture of positive electrode coating plates. The extrusion coating head simultaneously extrudes two slurries: ceramic slurry and active material slurry. However, at the interface between the two slurries, the two slurries blend into each other due to internal and external factors such as the extrusion pressure of the coating head, different slurry densities, mechanical vibration, and hot air blowing, causing the boundary to blur and produce ceramic virtual edges. Ceramic virtual edges can lead to reduced insulation performance, imbalanced battery safety performance, and imbalanced battery pack consistency. To address the above problems, this application provides the following technical solutions.

[0048] In the first aspect, the embodiment of the present invention provides a battery electrode production system, referring to Figure 1 , including: a coating back roller 50, a coating die 60, a first heating device 10 and a second heating device 20 arranged along the transmission direction of the current collector 30; the coating back roller 50 and the coating die 60 are arranged opposite to each other, the coating back roller 50 is used to support and transmit the current collector 30, and the coating die 60 is used to squeeze the slurry 40 onto the current collector 30; the first heating device 10 is used to heat the ceramic slurry 401 on the current collector for the first time, and the second heating device 20 is used to heat the ceramic slurry 401 and the active material slurry 402 on the current collector for the second time.

[0049] The coating back roller 50 serves as a supporting carrier for the current collector 30. It rotates to transmit the current collector and moves in a preset direction, ensuring that the current collector maintains a flat and stable tension state during the coating process. It cooperates with the coating die head 60 through mechanical transmission to form an extrusion coating working surface, providing basic support for the uniform coating of the slurry 40.

[0050] The coating die 60 transports the slurry 40 to the outlet through the internal flow channel. The slurry 40 includes adjacent ceramic slurry 401 and active material slurry 402 . The coating die 60 utilizes the gap between the coating die 60 and the coating back roller 50 to squeeze and coat the slurry on the surface of the current collector 30 .

[0051] The first heating device 10 heats the coated ceramic slurry 401 for the first time, and initially evaporates the solvent in the slurry by increasing the temperature, while promoting the bonding of the ceramic particles and the surface of the current collector to form a preliminarily solidified structure.

[0052] After the ceramic slurry 401 is initially solidified, the second heating device 20 heats the ceramic slurry 401 and the active material slurry 402 for a second time to further volatilize the solvent, thereby reducing the compatibility at the junction of the adjacent ceramic slurry 401 and the active material slurry 402, causing blurred boundaries and generating ceramic virtual edge problems.

[0053] The slurry 40 is dried in stages by providing a first heating device 10 for primary heating and a second heating device 20 for secondary heating. The first heating device 10 acts on the ceramic slurry 401, causing it to rapidly solidify at its center. This prevents unsolidified ceramic slurry from flowing toward the active material slurry 402, thereby reducing the possibility of the two slurries blending into each other due to internal and external factors such as different slurry densities, mechanical vibration, and hot air blowing, resulting in blurred boundaries and a resulting ceramic edge.

[0054] This targeted heating allows only the center of the ceramic slurry 401 to be heated during a single heating cycle, while the rest of the ceramic slurry 401 and the active material slurry 402 are then baked through the second heating device 20. This effectively avoids the problem of rapid crusting on the slurry surface and difficulty in evaporating the internal solvent due to a single high-temperature drying cycle. It also prevents cracking and other phenomena in the thinner areas at the edges of the ceramic slurry 401 due to long baking times. Therefore, the provision of the first heating device 10 and the second heating device 20 can reduce drying defects such as cracking and peeling in the electrode slurry, thereby ensuring the quality and performance of the electrode.

[0055] In addition, since the ceramic slurry 401 and the active material slurry 402 are arranged adjacent to each other, heating the ceramic slurry 401 can reduce excessive heating of the active material slurry 402 and reduce the risk of performance damage of the active material due to overheating. At the same time, it can also help the two slurries maintain good performance during the drying process, which is beneficial to the subsequent processing and use of battery electrodes.

[0056] Therefore, the first heating device 10 of the present application can bake only the center of the ceramic slurry 401 during a single heating cycle, causing the center of the ceramic slurry 401 to solidify rapidly. This prevents unsolidified ceramic slurry from flowing toward the active material slurry 402, effectively reducing the problem of ceramic edge artifacts caused by the ceramic slurry flowing toward the active material slurry. It can also effectively reduce the problem of rapid crusting on the slurry surface and difficulty in volatilizing the internal solvent caused by a single high-temperature drying cycle.

[0057] In one embodiment, reference Figure 1 、 Figure 7 The first heating device 10 further includes an isolation cover 101 and a heating head 102; the isolation cover 101 is provided on the heating head 102; the heating head 102 is used to perform a first heating on the ceramic slurry 401 on the current collector.

[0058] The isolation cover 101 is arranged on the side of the heating head 102 away from the current collector 30 and covers the heating head 102, which can isolate the heating head 102 from the external environment, reduce the impact of external factors such as dust, water vapor, etc. on the heating head 102, and prevent it from being contaminated or damaged, thereby extending the service life of the heating device and ensuring the stability of its performance.

[0059] At the same time, the isolation cover 101 can reduce heat loss to the surrounding environment, allowing the heat generated by the heating head 102 to act more concentratedly on the ceramic slurry 401, improving heat utilization efficiency, thereby improving drying efficiency, shortening drying time, and promoting improved production efficiency. In addition, during the first heating process, the heating head 102 mainly dries the ceramic slurry 401, and the isolation cover 101 also helps to reduce heat diffusion and conduction to the active material slurry 402.

[0060] In one embodiment, reference Figure 5 、 Figure 6 The first heating device 10 further includes a slider 103 and a slide rail 104 ; the slider 103 is movably connected to the slide rail 104 , and the slider 103 is fixedly connected to the heating head 102 .

[0061] The slide rail 104 is arranged along the first direction Z. The slider 103 is movably connected to the slide rail 104 and fixedly connected to the heating head 101. The movement of the slider 103 on the slide rail 104 enables the heating head 101 to flexibly move in the first direction Z. The operator can precisely adjust the position of the heating head 101 in the first direction Z according to the specific position and thickness of the slurry 40 on the current collector 30 and the requirements of the drying process to ensure that the heating head 102 is located in the area where the ceramic slurry 401 is located, thereby heating the ceramic slurry 401 during the first heating process.

[0062] In one embodiment, the slide rail 104 is also adjustable in the thickness direction of the slurry 40. For example, the battery electrode production system is further provided with a slide rail bracket, and the slide rail 104 is movably mounted on the slide rail bracket along the third direction Y. By moving the slide rail 104 on the slide rail bracket, the position of the heating head 101 can be fine-tuned to ensure a more uniform application of the hot air flow to the surface of the slurry 40. For slight differences in thickness, position, etc. between different batches of current collectors 30 or slurry 40, the position of the heating head 101 can be adjusted to ensure consistency and uniformity of the drying process, thereby reducing differences in battery electrode performance caused by uneven drying.

[0063] This adjustable structure improves the device's adaptability to different battery electrode types and specifications. Whether processing slurry 40 with varying thicknesses or current collectors 30 of varying sizes, the position of the heating head 101 can be adjusted to meet drying requirements, expanding the device's applicability and reducing the cost of replacing or adjusting the equipment.

[0064] Second, reference Figure 8 , an embodiment of the present invention further provides a battery electrode drying method, comprising:

[0065] Step S101 , transporting the current collector 30 coated with the slurry 40 to the first heating device 10 ;

[0066] Step S102 , controlling the first heating device 10 to heat the ceramic slurry 401 on the current collector 30 for the first time;

[0067] Step S103 : transporting the current collector 30 to the second heating device 20 , and controlling the second heating device 20 to heat the ceramic slurry 401 and the active material slurry 402 on the current collector 30 for a second time.

[0068] The slurry 40 includes a ceramic slurry 401 and an active material slurry 402, which are adjacently arranged. A first heating device 10 is positioned above the ceramic slurry 401. During the drying process, the first heating device 10 can be controlled to heat the applied ceramic slurry 401 for the first time. This heating process initially evaporates the solvent in the slurry, promotes bonding between the ceramic particles and the current collector surface, and forms a preliminarily solidified structure.

[0069] After the ceramic slurry 401 completes preliminary solidification, the current collector 30 is transported to the second heating device 20, which heats the ceramic slurry 401 and the active material slurry 402 for a second time to further evaporate the solvent, reduce the compatibility at the junction of the adjacent ceramic slurry 401 and the active material slurry 402, cause blurred boundaries, and produce ceramic virtual edge problems.

[0070] The slurry 40 is dried in stages by providing a first heating device 10 for primary heating and a second heating device 20 for secondary heating. The first heating device 10 acts on the ceramic slurry 401, causing it to rapidly solidify at its center. This prevents unsolidified ceramic slurry from flowing toward the active material slurry 402, thereby reducing the possibility of the two slurries blending into each other due to internal and external factors such as different slurry densities, mechanical vibration, and hot air blowing, resulting in blurred boundaries and a resulting ceramic edge.

[0071] Because the fluidity and required drying temperatures of the ceramic slurry 401 and the active material slurry 402 are different, heating them twice allows only the ceramic slurry 401 to be heated in one heating step, while the active material slurry 402 is then baked through the second heating device 20. This effectively avoids the problem of rapid crusting on the slurry surface and difficulty in volatilizing the internal solvent caused by a single high-temperature drying step, and also avoids cracking and other phenomena caused by the thinner areas at the edges of the ceramic slurry 401 due to long baking times. Therefore, the provision of the first heating device 10 and the second heating device 20 can reduce drying defects such as cracking and peeling of the electrode slurry, thereby ensuring the quality and performance of the electrode.

[0072] In addition, since the ceramic slurry 401 and the active material slurry 402 are arranged adjacent to each other, heating the ceramic slurry 401 can reduce excessive heating of the active material slurry 402 and reduce the risk of performance damage of the active material due to overheating. At the same time, it can also help the two slurries maintain good performance during the drying process, which is beneficial to the subsequent processing and use of battery electrodes.

[0073] refer to Figure 9 In one embodiment, the battery electrode drying method further includes:

[0074] Step S201: transporting the current collector 30 coated with the slurry 40 to the first heating device 10;

[0075] Step S202: Continuously acquiring a plurality of thickness values ​​of the ceramic slurry 401 along a third direction Y at a preset interval from the boundary toward the center of the ceramic slurry 401 using a detector; wherein the third direction Y is the thickness direction of the slurry;

[0076] Step S203: determining a first region 4011 and a second region 4012 according to the plurality of thickness values, wherein the thickness of the first region 4011 is greater than the thickness of the second region 4012;

[0077] Step S204: controlling the first heating device 10 to heat the first area 4011;

[0078] Step S205 : transporting the current collector 30 to the second heating device 20 , and controlling the second heating device 20 to heat the ceramic slurry 401 and the active material slurry 402 on the current collector 30 for a second time.

[0079] refer to Figure 2 、 Figure 3 and Figure 4 In the plane where the current collector 30 is located, there is a first direction Z and a second direction X that are perpendicular to each other. The width direction of the slurry is the first direction Z, the transmission direction of the current collector 30 is the second direction X, and the third direction Y is the thickness direction of the slurry. Along the first direction Z, the area where the ceramic slurry 401 is located includes a first area 4011 and a second area 4012, and the first area 4011 is located between the two second areas 4012.

[0080] Because the ceramic slurry 401 has a certain degree of fluidity, a gradually decreasing meniscus will form at the edge of the slurry when it is not dried due to the combined effects of the liquid's surface tension and adhesion. That is, along the first direction Z, the thickness of the edge of the ceramic slurry 401 along the third direction Y is less than the thickness of the central region along the third direction Y. Therefore, the ceramic slurry 401 is divided into a first region 4011 and a second region 4012 along the first direction Z, wherein the width of the ceramic slurry 401 along the first direction Z is d, the width of the first baked region 4011 along the first direction Z is a, and a<d; the portion between the boundary of the first region 4011 and the boundary of the ceramic slurry 401 along the first direction Z is the second region 4012; and the width of the first unbaked region 4012 along the first direction Z is b, and d=a+b.

[0081] In order for the first heating device 10 to heat the first area 4011, the positions of the first area 4011 and the second area 4012 must be determined first, and the thickness of the ceramic slurry 401 along the third direction Y is measured by a measuring device to determine the boundary position between the first area 4011 and the second area 4012.

[0082] refer to Figure 4 The thickness of the first region 4011 is h1, and the thickness of the second region 4012 is less than h1. After determining the boundary position between the first region 4011 and the second region 4012, it can be ensured that during the first heating, only the first region 4011 with a thickness of h1 is baked, which can make the center position of the ceramic slurry 401 solidify quickly and will not flow to the side of the active material slurry 402, which can further reduce the problem of virtual edges caused by the ceramic slurry 401 flowing to the active slurry material.

[0083] Since the heat flowing out of the heating head 101 of the first heating device 10 will produce thermal diffusion, controlling the first heating device 10 to heat the first area 4011 can ensure that the heat directly acts on the first area 4011 of the ceramic slurry 401 that needs to be dried, so that the first area 4011 can obtain sufficient heat and achieve efficient and uniform drying. In the process of heating the first area 4011, due to thermal diffusion, the heat will be transferred to the second area 4012, so that a large amount of heat is concentrated on the first area 4011, reducing heat loss and waste, effectively utilizing thermal energy, shortening drying time, and improving production efficiency. And because the thickness of the second area 4012 along the third direction Y is relatively thin, heating only the first area 4011 can also ensure that the second area 4012 at the edge will not be overheated and produce cracking, etc., further ensuring the quality of the electrode.

[0084] In one embodiment, in step S203, the method further includes:

[0085] Among the multiple thickness values, the first detected thickness value is equal to the target position corresponding to the target thickness value to determine the first area 4011 and the second area 4012; the target thickness value is the thickness value of the center position of the ceramic slurry 401 along the first direction Z in the third direction Y;

[0086] Alternatively, when the thickness values ​​detected multiple times are the same, the first area 4011 and the second area 4012 are determined based on the position corresponding to the thickness value detected for the first time among the multiple times of the same thickness values ​​detected.

[0087] When determining the boundary between the first area 4011 and the second area 4012, refer to Figure 4 , the following two methods can be used:

[0088] First, among multiple thickness values, the first detected thickness value is equal to the target position corresponding to the target thickness value to determine the first area 4011 and the second area 4012; the target thickness value is the thickness value of the center position of the ceramic slurry 401 along the first direction Z in the third direction Y.

[0089] Based on historical data or preset thickness values, the target thickness value h2 to be detected is determined, and measurement is made from the edge of the ceramic slurry 401 along the first direction Z to the center. By capturing the first position equal to the target thickness value h2, the boundary between the first area 4011 and the second area 4012 can be determined.

[0090] Secondly, continuous measurement is performed from the edge to the center of the ceramic slurry 401 along the first direction Z. As the measurement position changes, the measured results will also increase. When the same thickness h2 is detected multiple times, the first area 4011 has been detected. The same thickness h2 measured multiple times is the thickness of the first area 4011. The position where the thickness h2 is measured for the first time is the dividing line between the first area 4011 and the second area 4012. The position where the thickness h2 is first detected is used as the reference for area division, which can avoid boundary offset caused by selecting an intermediate point or a random point.

[0091] After determining the boundary position between the first area 4011 and the second area 4012, it can be ensured that during the first heating, only the first area 4011 with a thickness of h1 is baked, and the second area 4012 is heated through heat transfer, thereby further improving the drying quality of the electrode, avoiding the occurrence of virtual edges, and preventing the second area 4012 from cracking, warping, and the like.

[0092] In one embodiment, controlling the first heating device 10 to heat the first area 4011 further includes:

[0093] The heating head 102 is controlled to face the first area 4011 , and the orthographic projection of the heating head 102 on the first area 4011 is located within the range of the first area 4011 .

[0094] The orthographic projection of the heating head 102 on the first region 4011 is located within the range of the first region 4011. This ensures that during a single baking, the heat generated by the heating head 102 can effectively act on the first region 4011, causing the first region 4011 to solidify rapidly, while also preventing the heat from directly acting on the second region 4012, which could cause overheating of the ceramic slurry in the second region 4012. This targeted heating ensures that only the first region 4011 is heated during a single heating cycle, while the second region 4012 and the active material slurry 402 are then baked via the second heating device 20. This improves heat utilization and drying efficiency, while further ensuring the quality of the electrode.

[0095] In some embodiments, along the first direction Z, the ceramic slurry 401 has a center of symmetry, and the center of symmetry is located in the first region 4011. In the step of controlling the heating head 102 to face the first region 4011, the orthographic projection of the heating head 102 in the first region 4011 is controlled to be located at the center of symmetry.

[0096] And / or, the first heating device 10 further includes an isolation cover 101 ; the isolation cover 101 is disposed on the heating head 102 ; during the first heating process, the orthographic projection of the isolation cover 101 on the first area 4011 is controlled to be within the range of the first area 4011 .

[0097] The symmetry center of the ceramic slurry 401 refers to the symmetry center of the ceramic slurry 401 in the first direction Z. Due to the fluidity of the ceramic slurry 401 , the symmetry center of the ceramic slurry 401 in the first direction Z coincides with the symmetry center of the first region in the first direction Z.

[0098] When the center of the orthographic projection of the heating head 102 within the first region 4011 coincides with the center of symmetry, the heat generated by the heating head 102 radiates from the center of symmetry to the surrounding area. This symmetrical thermal field prevents cracking of the slurry due to unilateral overheating. Aligning the heating head 102 with the center evenly distributes the heat flux in the third direction Y, avoiding cracking caused by localized overheating. This arrangement makes the heating more targeted, improves the accuracy of the heated area, and avoids cracking and other phenomena caused by long baking times at the thinner edges of the second region 4012.

[0099] The isolation cover 101 is disposed on the heating head 102, isolating the heating head 102 from the external environment. This reduces the impact of external factors such as dust and moisture on the heating device, preventing contamination or damage, thereby extending the service life of the heating device and ensuring its stable performance. The orthographic projection of the isolation cover 101 on the first area 4011 is located within the first area 4011, ensuring that the heat generated by the heating head 102 is concentrated within the first area 4011, reducing heat loss to the surrounding environment, improving heat utilization efficiency, and thereby enhancing drying efficiency, shortening drying time, and facilitating increased production efficiency.

[0100] In addition, an exhaust duct can be provided on the isolation cover 101 to promptly discharge moisture and exhaust gases generated during the drying process, preventing moisture from accumulating inside the device and affecting the drying effect and the quality of the battery electrodes. Exhausting exhaust gases also helps maintain a clean and safe working environment, reducing the health risks of harmful gases to operators.

[0101] By discharging moisture and waste gas through the exhaust pipe, the stability of the drying environment in the isolation cover 101 can be maintained, and the consistency of parameters such as temperature and humidity during the drying process can be ensured, which is conducive to improving the uniformity and quality stability of the battery electrode drying and reducing product quality differences caused by changes in environmental factors.

[0102] In some embodiments, the width of the first region 4011 along the first direction Z is a, the width of the heating head 102 in the first direction Z is c, and 0.5a≤c <a;

[0103] And / or, the heating temperature of the first heating is 80 to 140° C., and the heating time is 0.2 to 0.8 seconds.

[0104] Since the hot air flowing out of the heating head 102 will diffuse, the width c of the projection of the heating head 102 along the first direction Z is half the width a of the first area 4011 along the first direction Z, and the projection of the heating head 102 is located at the center of the first area 4011 along the first direction Z. This arrangement ensures that the hot air flow directly acts on the center of the first area 4011 of the ceramic slurry 401 that requires intensive drying, so that the first area 4011 can obtain sufficient heat to achieve efficient and uniform drying. It also prevents excessive concentration or dispersion of heat, which could cause the ceramic slurry 401 to crack, deform, or otherwise suffer performance damage due to excessive heat. This facilitates uniform drying of the ceramic slurry 401 in this area, thereby helping to improve the quality and performance consistency of the battery electrode sheets.

[0105] Due to different material formulas, the solid content and designed thickness of the ceramic slurry 401 are different, resulting in different heating and drying times. Therefore, the heating temperature of the first heating is set between 80°C and 140°C, and the heating time is set between 0.2 seconds and 0.8 seconds. According to the different formulas of the ceramic slurry 401, the heating temperature and heating time are flexibly adjusted to ensure the drying effect and quality of the electrode.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pole piece production system, characterized in that: include: A coating back roller (50), a coating die head (60), a first heating device (10), and a second heating device (20) arranged along a conveying direction of the current collector (30); The coating back roller (50) and the coating die head (60) are arranged opposite to each other, the coating back roller (50) is used to support and transport the current collector (30), and the coating die head (60) is used to squeeze the slurry (40) onto the current collector (30); The first heating device (10) is used to heat the ceramic slurry (401) on the current collector for the first time, and the second heating device (20) is used to heat the ceramic slurry (401) and active material slurry (402) on the current collector for the second time.

2. The battery pole piece production system according to claim 1, characterized in that: The first heating device (10) further comprises an isolation cover (101) and a heating head (102); the isolation cover (101) is provided on the heating head (102); and the heating head (102) is used for performing a first heating on the ceramic slurry (401) on the current collector.

3. The battery pole piece production system according to claim 2, characterized in that: The first heating device (10) further includes a slider (103) and a slide rail (104); The slider (103) is movably connected to the slide rail (104), and the slider (103) is fixedly connected to the heating head (102).

4. A method for drying a battery electrode, characterized in that: include: The current collector (30) coated with the slurry (40) is transported to a first heating device (10); the slurry (40) includes a ceramic slurry (401) and an active material slurry (402); the ceramic slurry (401) and the active material slurry (402) are adjacently arranged on the same side of the current collector (30); controlling the first heating device (10) to heat the ceramic slurry (401) on the current collector (30) for the first time; The current collector (30) is transported to a second heating device (20), and the second heating device (20) is controlled to heat the ceramic slurry (401) and the active material slurry (402) on the current collector (30) for a second time.

5. The battery pole piece drying method according to claim 4, characterized in that: In the plane where the current collector (30) is located, there is a first direction (Z) and a second direction (X) perpendicular to each other, the width direction of the slurry is the first direction (Z), the transmission direction of the current collector (30) is the second direction (X), and along the first direction (Z), the area where the ceramic slurry (401) is located includes a first area (4011) and a second area (4012), and the first area (4011) is located between the two second areas (4012); The step of controlling the first heating device (10) to heat the ceramic slurry (401) on the current collector (30) for the first time comprises: The first heating device (10) is controlled to heat the first region (4011).

6. The battery pole piece drying method according to claim 5, characterized in that: Before controlling the first heating device (10) to heat the first area (4011), the method further comprises: From the boundary toward the center of the ceramic slurry (401), a plurality of thickness values ​​of the ceramic slurry (401) along a third direction (Y) are continuously acquired by a detector at a preset interval; wherein the third direction (Y) is the thickness direction of the slurry; The first region (4011) and the second region (4012) are determined based on the multiple thickness values, wherein the thickness of the first region (4011) is greater than the thickness of the second region (4012).

7. The battery pole piece drying method according to claim 6, characterized in that: The step of determining the first region (4011) and the second region (4012) according to the plurality of thickness values, wherein the thickness of the first region (4011) is greater than the thickness of the second region (4012), comprises: The first region (4011) and the second region (4012) are determined by taking a target position corresponding to a first detected thickness value among the plurality of thickness values; the target thickness value is a thickness value of a center position of the ceramic slurry (401) along the first direction (Z) in the third direction (Y); Alternatively, when the thickness values ​​detected multiple times are the same, the first area (4011) and the second area (4012) are determined based on the position corresponding to the thickness value detected for the first time among the multiple times of the same thickness values ​​detected.

8. The battery pole piece drying method according to claim 5, characterized in that: The first heating device (10) comprises a heating head (102), and the step of controlling the first heating device (10) to heat the first area (4011) comprises: The heating head (102) is controlled to face the first area (4011), and the orthographic projection of the heating head (102) on the first area (4011) is located within the range of the first area (4011).

9. The battery pole piece drying method according to claim 8, characterized in that: Along the first direction (Z), the ceramic slurry (401) has a center of symmetry, the center of symmetry being located within the first region (4011), and in the step of controlling the heating head (102) to face the first region (4011), the orthographic projection of the heating head (102) within the first region (4011) is controlled to be located at the center of symmetry; And / or, the first heating device (10) further comprises an isolation cover (101); the isolation cover (101) is arranged to cover the heating head (102); and during the first heating process, the orthographic projection of the isolation cover (101) on the first area (4011) is controlled to be within the range of the first area (4011).

10. The battery pole piece drying method according to claim 8, characterized in that: The width of the first region (4011) along the first direction (Z) is a, and the width of the heating head (102) in the first direction (Z) is c, satisfying 0.5a≤c <a; And / or, the heating temperature of the first heating is 80° C. to 140° C., and the heating time is 0.2 seconds to 0.8 seconds.

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