Pole heating device, pole production system and method

Abstract

The present application discloses a pole piece heating device, a pole piece production system and a method, wherein the pole piece heating device (10) comprises: a box (1); two roller groups (2) installed in the box (1), the two roller groups (2) are arranged at intervals along a first direction (x), and each roller group (2) comprises a plurality of first guide rollers (21) arranged at intervals along a second direction (y), so that the pole piece (4) can alternately pass around all the first guide rollers (21) in the two roller groups (2) in sequence, and the second direction (y) is perpendicular to the first direction (x); and a heating component (3) installed in the box (1) and configured to heat the coated pole piece (4).

Description

Technical Field

[0001] The present application relates to the technical field of pole piece production system production, and specifically to a pole piece heating device, a pole piece production system and a method. Background Art

[0002] Lithium-ion batteries have been widely used in electric vehicles due to their advantages such as high energy density, high power density, many cycles and long storage time.

[0003] The electrode assembly in the battery includes a pole piece, which has a current collector, and an active material is coated on the surface of the current collector. After coating, the pole piece enters an oven for drying. However, the drying efficiency of the pole piece is still the main factor restricting the acceleration of pole piece coating. Summary of the invention

[0004] The present application proposes a pole piece heating device, a pole piece production system and a pole piece production method, which can improve the drying efficiency of the pole piece.

[0005] According to a first aspect of the present application, a pole piece heating device is provided, comprising:

[0006] Box;

[0007] Two roller groups are installed in the box, the two roller groups are spaced apart along a first direction, each roller group includes a plurality of first guide rollers spaced apart along a second direction, so that the pole piece can alternately pass around all the first guide rollers in the two roller groups in sequence, and the second direction is perpendicular to the first direction; and

[0008] The heating assembly is installed in the box and is configured to heat the coated electrode.

[0009] This embodiment forms a curved extension path by arranging two roller groups in the box and making the pole piece bypass the multiple first guide rollers in the two roller groups alternately in sequence, which can extend the extension length of the pole piece in the box. If the pole piece runs at the same speed, it is beneficial for the pole piece to stay longer in the box when heated, which can optimize the drying effect and improve the drying efficiency. If the pole piece achieves the same drying effect, the running speed of the pole piece can be increased. Therefore, this pole piece heating device can optimize the drying effect and improve the drying efficiency, thereby indirectly increasing the coating speed of the pole piece.

[0010] Moreover, the pole piece is supported by the first guide roller in the box, which can keep the position stable, prevent deviation, curling or scratching, and improve the process performance of the pole piece after drying. In addition, the support of the first guide roller will keep the pole piece in a taut state with a certain tension, preventing the pole piece from wrinkling during the heating process, and the pole piece can be in a moving state during the heating process, which is not easy to bend and shape, and is conducive to subsequent winding.

[0011] In some embodiments, the plurality of first guide rollers of each of the two roller groups are staggered along the second direction.

[0012] This embodiment can make the extension path of the pole piece wavy, which can reduce the bending degree of the pole piece, facilitate the winding of the pole piece after heating, and prevent wrinkles on the pole piece from affecting the performance of the electrode assembly.

[0013] In some embodiments, the axis of the first guide roller is arranged along a third direction, and the third direction is perpendicular to the first direction and the second direction.

[0014] This arrangement facilitates the installation of the first guide roller, and after the pole piece enters the box body perpendicular to the first direction, it can smoothly bypass the first guide roller to prevent the pole piece from twisting, making the movement of the pole piece in the box body smoother and heating each position of the pole piece evenly.

[0015] In some embodiments, the first guide roller is rotatably arranged around its own axis, and the first guide rollers in the two roller groups rotate in opposite directions.

[0016] In this embodiment, the first guide roller is rotatably arranged around its own axis, so that rolling friction is formed between the pole piece and the first guide roller, which can reduce the friction force on the pole piece during movement, prevent scratches or wear on the active material coated on the pole piece, and help control the tension force on the pole piece, so that the heating effect on the pole piece is more uniform. Optionally, the first guide roller can also be kept fixed to form sliding friction between the pole piece and the first guide roller.

[0017] In some embodiments, the box body is provided with an inlet and an outlet, and the inlet and the outlet are respectively located on two side walls of the box body perpendicular to the second direction;

[0018] The pole piece heating device also includes:

[0019] A second guide roller, located between the two roller groups and the inlet along the second direction and corresponding to the inlet position along the first direction, and configured to provide guidance for the length section of the pole piece from the inlet to the first first guide roller; and

[0020] The third guide roller is located between the two roller groups and the outlet along the second direction and corresponds to the outlet position along the first direction, and is configured to provide guidance for the pole piece from the last first guide roller to the outlet.

[0021] This embodiment provides a second guide roller and a third guide roller to guide the electrode when it enters the box through the inlet or is led out through the outlet, preventing the electrode from contacting the inlet or outlet and causing wear of the active material, and guiding the electrode to the first first guide roller or leading it out from the last first guide roller along a suitable path, and also maintaining the tension on the electrode.

[0022] In some embodiments, the heating assembly includes multiple heating components, which are located between two roller groups along the first direction and are spaced apart along the second direction. In the second direction, the multiple heating components are at least arranged between every two adjacent first guide rollers, and the heating components are configured to heat the length segments of the electrode sheet located on both sides of the heating components along the second direction.

[0023] The heating component in this embodiment is located between two adjacent length segments of the electrode piece, and can heat the length segments on both sides at the same time through the heating component. Compared with the method of arranging the heating component at the top or bottom of the box to heat the electrode piece on one side, the heat emitted by the heating component can be fully utilized to make the energy distribution of the heating component uniform, increase the heating time of the electrode piece in the box, and thus improve the drying efficiency of the electrode piece.

[0024] In some embodiments, a plurality of heating components may be arranged side by side along the first direction between two adjacent first guide rollers.

[0025] This embodiment can dry a larger area of ​​the electrode, thereby making the drying of the electrode more uniform and improving the drying efficiency.

[0026] In some embodiments, the heating component includes a heating element and a protective cover, and the protective cover is sleeved outside the heating element.

[0027] This embodiment provides a protective cover for the heating element to prevent the high-temperature area of ​​the heating element from directly heating the pole piece or components in the box, so that the heating temperature is more controlled, thereby improving the safety of the heating component, and reliably controlling the heating temperature of the pole piece within a suitable process temperature range, and preventing damage to other components in the box.

[0028] In some embodiments, the heating element is an infrared heating element, the protective cover is made of a light-transmitting material, and at least one of the protective cover and the infrared heating element is provided with a light-blocking layer at both ends along the first direction, so that the infrared light emitted by the infrared heating element is irradiated toward both sides along the second direction.

[0029] This embodiment provides a light-transmitting protective cover and provides light-blocking layers at both ends of at least one of the protective cover and the infrared heating element along the first direction. This not only meets the requirement of the infrared heating element to irradiate infrared light toward the length sections on both sides of the pole piece for heating, but also prevents the infrared light from irradiating other components in the box. On the basis of ensuring the drying effect of the pole piece, the reliability and safety of the pole piece heating device are improved.

[0030] In some embodiments, the first direction is the height direction of the box.

[0031] This embodiment can make the electrode piece present an up and down wavy shape, that is, the amplitude of the electrode piece extension curve is along the height direction of the box body, and can make the extension direction of the electrode piece adapt to the extension direction of the electrode piece in the current two processes of the electrode piece coating device and the electrode piece drying device, so that the movement of the electrode piece is smoother, and wrinkles can be prevented from being generated on the electrode piece, thereby improving the process performance of the electrode piece after drying.

[0032] In some embodiments, the pole piece heating device further includes a cooling assembly, which is disposed outside the box and is configured to cool the heated pole piece.

[0033] This embodiment can quickly reduce the temperature of the pole piece after drying the pole piece, so as to prevent the subsequent measurement and winding process of the pole piece from being affected.

[0034] In some embodiments, the cooling assembly includes a cooling roller configured to cool fluid passing around it.

[0035] This embodiment provides a cooling roller so that the pole piece can be fitted with the outer surface of the cooling roller to achieve cooling. Good fitting can improve the cooling effect and has low cost.

[0036] In some embodiments, a recovery port is provided on the box body, and the pole piece heating device further includes a collecting component configured to collect steam and chemical gases generated in the box body during the heating process through the recovery port.

[0037] This embodiment takes into account that water vapor and chemical gases will be generated during the heating process of the electrode. During the heating process or after the heating is completed, the water vapor and chemical gases in the box are collected by the collecting component through negative pressure, so that the box can maintain a dry environment, improve the drying efficiency, and prevent the chemical gas from corroding the electrode or other components in the box, thereby ensuring the process performance of the electrode after drying and increasing the service life of the electrode heating device.

[0038] According to a second aspect of the present application, a pole piece production system is provided, comprising:

[0039] A pole piece coating device, configured to coat the active material in the pole piece;

[0040] A pole piece drying device, disposed downstream of the pole piece coating device, configured to bake the coated pole piece; and

[0041] The electrode heating device of the above embodiment is arranged downstream of the electrode drying device and is configured to reheat the electrode after baking.

[0042] The electrode production system of this embodiment arranges an electrode heating device downstream of the electrode drying device, and can perform preliminary drying on the electrode by the electrode drying device, and then enter the electrode heating device for secondary drying, which can optimize the drying effect of the electrode and shorten the residence time of the electrode in the electrode drying device, thereby increasing the movement speed of the electrode and thus increasing the coating rate of the electrode.

[0043] According to a third aspect of the present application, a method for producing a pole piece is provided, comprising:

[0044] Applying active material in the pole piece by a pole piece coating device;

[0045] Baking the coated electrode by an electrode drying device; and

[0046] The baked electrode is reheated by the electrode heating device of the above embodiment.

[0047] In some embodiments, the pole piece is in motion during the coating, baking and reheating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0049] Figure 1 Schematic diagram of the module composition of some embodiments of the electrode production system of the present application.

[0050] Figure 2 Schematic diagram of the structure of some embodiments of the electrode heating device of the present application.

[0051] Figure 3 These are front views of some embodiments of the heating components in the pole piece heating device of the present application.

[0052] Figure 4 It is a schematic diagram of the side structure of some embodiments of the heat-generating element in the heating component.

[0053] Figure 5 Schematic diagram of the end structure of some embodiments of the heating element in the heating component.

[0054] Figure 6 Schematic diagram of the process flow of some embodiments of the electrode production method of the present application.

[0055] In the drawings, the drawings are not drawn to scale.

[0056] Marking Description:

[0057] 10. Pole heating device; 20. Pole coating device; 30. Pole drying device;

[0058] 1. Box body; 11. Inlet; 12. Outlet; 13. Recovery port; 1A. Side wall; 1B. Top wall; 1C. Bottom wall;

[0059] 2. Roller group; 21. First guide roller;

[0060] 3. Heating assembly; 3', heating component; 31, heating element; 311, tungsten wire; 32, protective cover; 321, first opening; 322, second opening; 323, flange; 33, light blocking layer;

[0061] 4. Pole piece;

[0062] 5. Second guide roller;

[0063] 6. The third guide roller;

[0064] 7. Cooling assembly; 71. Cooling box; 711. Opening; 72. Cooling roller; 73. Fourth guide roller;

[0065] 8. Collect parts;

[0066] 9. driving assembly; 91. power component; 92. flexible transmission component;

[0067] x, first direction; y, second direction; z, third direction. DETAILED DESCRIPTION

[0068] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0069] In the description of the present application, it should be noted that, unless otherwise specified, “plurality” means more than two; the terms “upper”, “lower”, “left”, “right”, “inside”, “outside”, etc., indicating directions or positional relationships, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application.

[0070] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but within the tolerance range. "Parallel" is not strictly parallel, but within the tolerance range. The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the present application.

[0071] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0072] Reference to "embodiments" herein means that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least some embodiments of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0073] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0074] The present application uses descriptions such as "upper", "lower", "top", "bottom", "front", "back", "inside" and "outside" to indicate directions or positional relationships. This is only for the convenience of describing the present application, and does not indicate or imply that the device referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it should not be understood as limiting the scope of protection of the present application.

[0075] The battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., which is not limited in the embodiments of the present application. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., which is not limited in the embodiments of the present application. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, which is not limited in the embodiments of the present application.

[0076] The current battery cell usually includes a shell and an electrode assembly contained in the shell, and the shell is filled with electrolyte. The electrode assembly is mainly formed by stacking or winding a first pole sheet and a second pole sheet with opposite polarities, and a separator is usually provided between the first pole sheet and the second pole sheet. The part of the first pole sheet and the second pole sheet coated with active material constitutes the main body of the electrode assembly, and the part of the first pole sheet and the second pole sheet not coated with active material each constitutes a first pole ear and a second pole ear. In a lithium-ion battery, the first pole sheet can be a positive pole sheet, including a positive current collector and a positive active material layer arranged on both sides of the positive current collector, the material of the positive current collector can be, for example, aluminum, and the positive active material can be, for example, lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide; the second pole sheet can be a negative pole sheet, including a negative current collector and a negative active material layer arranged on both sides of the negative current collector, the material of the negative current collector can be, for example, copper, and the negative active material can be, for example, graphite or silicon. The first pole ear and the second pole ear can be located at one end of the main body or at both ends of the main body respectively. During the charge and discharge process of the battery cell, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the terminals to form a current loop.

[0077] After the active material is coated on the surface of the current collector, the electrode of the electrode assembly needs to be placed in an oven for drying. During the drying process of the electrode, air pressure is applied to the two opposite surfaces to keep the electrode in a suspended state.

[0078] The inventors noticed that, in order to ensure the drying effect of the coating layer, the coated part of the electrode needs to stay in the oven for a long time, resulting in low drying efficiency of the electrode. Moreover, coating and drying are two continuous process links. During this process, the electrode is always in motion, so low drying efficiency is also the main factor restricting the speed of electrode coating. Moreover, during the drying process, the electrode is prone to scratches, curling or offset.

[0079] In order to solve the problem of low drying efficiency, the inventor thought of adding a hot air device and an infrared device in the oven at the same time, and using thermal oil as the heating source of the hot air device. At the same time, the thermal oil will also stimulate the infrared device to emit infrared rays to dry the electrode. Although this method can optimize the drying effect of the coating layer to a certain extent and improve the drying efficiency of the coating layer, this method will lead to a complex structure of the heating device, and the introduction of thermal oil will also affect the safety of the oven and easily pollute the internal environment of the oven. Moreover, this method cannot solve the problems of scratches, curling or offset of the electrode during the drying process.

[0080] In order to avoid excessive increase in the complexity of the heating structure, the inventors thought of increasing the time the pole piece stays in the oven, and prolonging the heating time of the pole piece without reducing the coating speed, which requires increasing the running path of the pole piece in the box. In addition, the pole piece can be supported to maintain a stable position, and the pole piece will not be scratched, curled or offset during the drying process.

[0081] According to this idea, the present application provides an improved electrode heating device, comprising: a box, two roller groups and a heating component. The two roller groups are installed in the box, the two roller groups are arranged at intervals along the first direction, and each roller group includes a plurality of first guide rollers arranged at intervals along the second direction, so that the electrode can alternately pass around all the first guide rollers in the two roller groups in sequence, and the second direction is perpendicular to the first direction; the heating component is installed in the box and is configured to heat the coated electrode.

[0082] This type of electrode heating device can extend the extension length of the electrode in the box by arranging multiple first guide rollers in the box and allowing the electrode to bypass the first guide rollers, which is beneficial for the electrode to stay in the box for a longer time, optimize the drying effect, and improve the drying efficiency, thereby indirectly increasing the coating speed of the electrode.

[0083] like Figure 1 As shown, such a pole piece heating device can be used in a pole piece production system, and the pole piece production system may include: a pole piece coating device 20 , a pole piece drying device 30 and a pole piece heating device 10 .

[0084] Among them, the electrode coating device 20 is configured to coat the active material in the electrode 4, for example, using a coating machine. If the electrode 4 is a positive electrode, the positive electrode active material is coated, and if the electrode 4 is a negative electrode, the negative electrode active material is coated; the electrode drying device 30 is arranged downstream of the electrode coating device 20, and is configured to bake the coated electrode 4, for example, using an oven; the electrode heating device 10 is arranged downstream of the electrode drying device 30, and is configured to reheat the baked electrode 4.

[0085] Among them, the electrode 4 can be in a long strip structure. During the coating and heating process of the electrode 4, the electrode coating device 20 can be used to control the electrode 4 to move at a preset coating speed. The electrode coating device 20, the electrode drying device 30 and the electrode heating device 10 are arranged in sequence along the movement direction of the electrode 4.

[0086] This electrode production system arranges an electrode heating device 10 downstream of the electrode drying device 30, and can perform preliminary drying on the electrode 4 through the electrode drying device 30, and then enter the electrode heating device 10 for secondary drying, which can optimize the drying effect of the electrode 4 and shorten the residence time of the electrode 4 in the electrode drying device 30, thereby increasing the movement speed of the electrode 4 and thus increasing the coating rate of the electrode 4.

[0087] Optionally, this type of electrode heating device 10 can also be directly used as the electrode drying device 30. The electrode drying device 30 using the improved points of the present application can also improve the drying efficiency of the electrode 4.

[0088] In some embodiments, the electrode production system may further include a winding device, which is disposed downstream of the electrode heating device 10 and is configured to wind up the electrode 4 after heating and drying for use in preparing an electrode assembly.

[0089] The structure of the pole piece heating device 10 will be described below.

[0090] In some embodiments, Figure 2 As shown, the electrode heating device 10 of the present application includes: a box body 1, two roller groups 2 and a heating assembly. The two roller groups 2 are installed in the box body 1, and the two roller groups 2 are arranged at intervals along the first direction x. Each roller group 2 includes a plurality of first guide rollers 21 arranged at intervals along the second direction y, so that the electrode 4 can alternately pass around all the first guide rollers 21 in the two roller groups 2 in sequence, and the second direction y is perpendicular to the first direction x; the heating assembly 3 is installed in the box body 1 and is configured to heat the coated electrode 4.

[0091] The box body 1 may be a rectangular parallelepiped or other shapes, and the multiple first guide rollers 21 in each roller group 2 may be fixed to the box body 1 by their ends, for example, a mounting hole is provided on the inner wall of the box body 1, and the ends of the first guide rollers 21 are inserted into the mounting hole for installation. The first guide roller 21 may be cylindrical and include at least a guide section along its own axial direction, and the outer surface of the guide section is wound with the pole piece 4 to provide a stable support force for the pole piece 4.

[0092] The multiple first guide rollers 21 in each roller group 2 are arranged at intervals along the second direction y, including both the case where the centers of the multiple first guide rollers 21 are in the same straight line and the case where the centers of the multiple first guide rollers 21 deviate from the same straight line along the first direction x.

[0093] The spacing between two adjacent first guide rollers 21 in the same roller group 2 can be equal, or the spacing between two adjacent first guide rollers 21 in one roller group 2 is also equal to the spacing between two adjacent first guide rollers 21 in another roller group 2, so that the pole piece 4 maintains a uniform extension path, thereby maintaining a uniform tension on the pole piece 4. Along the second direction y from one end to the other end of the box 1, the pole piece 4 alternately bypasses all the first guide rollers 21 in the two roller groups 2 in turn, so that the pole piece 4 extends in a wave shape.

[0094] The heating component 3 is installed in the box 1 and is configured to heat the coated electrode 4. The heating component 3 can be electrically heated, infrared heated or heated by hot air.

[0095] This embodiment forms a curved extension path by arranging two roller groups 2 in the box 1 and making the pole piece 4 bypass the multiple first guide rollers 21 in the two roller groups 2 alternately in sequence, which can extend the extension length of the pole piece 4 in the box 1. If the pole piece 4 runs at the same speed, it is beneficial for the pole piece 4 to stay longer in the box 1 when heated, which can optimize the drying effect and improve the drying efficiency. If the pole piece 4 achieves the same drying effect, the running speed of the pole piece 4 can be increased. Therefore, this pole piece heating device 10 can optimize the drying effect and improve the drying efficiency, thereby indirectly increasing the coating speed of the pole piece 4.

[0096] Moreover, the pole piece 4 is supported by the first guide roller 21 in the box 1, which can keep the position stable, prevent the occurrence of deviation, curling or scratching, and improve the process performance of the pole piece 4 after drying. In addition, the support of the first guide roller 21 will keep the pole piece 4 in a taut state with a certain tension, preventing the pole piece 4 from wrinkling during the heating process, and the pole piece 4 can be in a moving state during the heating process, and is not easy to bend and shape, which is conducive to subsequent winding.

[0097] In some embodiments, the first guide rollers 21 of the two roller groups 2 are staggered along the second direction y. For example, in the second direction y, the first guide roller 21 in one roller group 2 may be located in the middle of two adjacent first guide rollers 21 in the other roller group 2.

[0098] This embodiment can make the extension path of the pole piece 4 form a wave shape, which can reduce the bending degree of the pole piece 4, and is conducive to the winding of the pole piece 4 after heating, so as to prevent wrinkles on the pole piece 4 from affecting the performance of the electrode assembly.

[0099] Optionally, the plurality of first guide rollers 21 of each of the two roller groups 2 may also be arranged opposite to each other along the second direction y.

[0100] In some embodiments, the axis of the first guide roller 21 is disposed along a third direction z, and the third direction z is perpendicular to the first direction x and the second direction y.

[0101] This arrangement makes it easy to install the first guide roller 21, and after the pole piece 4 enters the box body 1 perpendicular to the first direction x, it can smoothly bypass the first guide roller 21 to prevent the pole piece 4 from twisting, making the movement of the pole piece 4 in the box body 1 smoother and making each position of the pole piece 4 heated evenly.

[0102] In some embodiments, the first guide roller 21 is rotatably arranged around its own axis, and the first guide rollers 21 in the two roller groups 2 rotate in opposite directions. For example, all the first guide rollers 21 in the two roller groups 2 can maintain a consistent rotation rate to ensure that the tension of the pole piece 4 along the length direction is consistent.

[0103] In order to rotate the first guide roller 21, Figure 2 As shown, the pole piece heating device 10 may also include a driving component 9, and the driving component 9 includes: a power component 91 and a flexible transmission component 92. Among them, the power component 91 can be arranged outside the box body 1, for example, an electric motor or a motor can be used. The flexible transmission component 92 bypasses a plurality of first guide rollers 21, and the first guide rollers 21 are rotatably arranged around their own axes. The driving component drives the plurality of first guide rollers 21 to rotate through the flexible transmission component 92. For example, the flexible transmission component 92 can be a belt or a chain. The power component 91 can transmit power to the flexible transmission component 92 through a driving wheel, and the driving wheel can be selected from a pulley or a sprocket.

[0104] The part of the first guide roller 21 that cooperates with the flexible transmission component 92 and the part that cooperates with the pole piece 4 are staggered along the axis of the first guide roller 21. For example, the part of the first guide roller 21 that cooperates with the flexible transmission component 92 is located in the end area, and the part that cooperates with the pole piece 4 is located in the middle area. This structure can separate the driving of the first guide roller 21 and the guiding of the pole piece 4, prevent mutual interference during operation, and improve the reliability of the operation of the pole piece heating device 10.

[0105] In one structure, the flexible transmission component 92 and the pole piece 4 are in the same path around the first guide roller 21, that is, all the first guide rollers 21 are driven to rotate by the same power component 91, and the first guide rollers 21 in the two roller groups 2 rotate in opposite directions. This structure can synchronize the rotation of all the first guide rollers 21, keep the pole piece 4 in uniform tension along the length direction, and reduce the number of power components 91. In another structure, two roller groups 2 are respectively provided with a power component 91 and a flexible transmission component 92, and this structure can reduce the difficulty of installing the flexible transmission component 92.

[0106] In this embodiment, the first guide roller 21 is rotatably arranged around its own axis, so that rolling friction is formed between the pole piece 4 and the first guide roller 21, which can reduce the friction force on the pole piece 4 during movement, prevent scratches or wear on the active material coated on the pole piece 4, and help control the tension force on the pole piece 4, so that the heating effect on the pole piece 4 is more uniform. Optionally, the first guide roller 21 can also be kept fixed to form sliding friction between the pole piece 4 and the first guide roller 21.

[0107] In some embodiments, Figure 2 As shown, the box body 1 is provided with an inlet 11 and an outlet 12, which are respectively located on two side walls 1A of the box body 1 perpendicular to the second direction y. The pole piece heating device 10 further includes: a second guide roller 5 and a third guide roller 6.

[0108] The second guide roller 5 is located between the two roller groups 2 and the inlet 11 along the second direction y, and corresponds to the position of the inlet 11 along the first direction x, and is configured to provide guidance for the pole piece 4 in the length section from the inlet 11 to the first first guide roller 21; the third guide roller 6 is located between the two roller groups 2 and the outlet 12 along the second direction y, and corresponds to the position of the outlet 12 along the first direction x, and is configured to provide guidance for the pole piece 4 in the length section from the last first guide roller 21 to the outlet 12.

[0109] Among them, the structure and installation form of the second guide roller 5 and the third guide roller 6 can be similar to the first guide roller 21. The second guide roller 5 corresponds to the position of the inlet 11 along the first direction x, and can guide the pole piece 4 to enter the box body 1 from the inlet 11 in a preset direction (for example, parallel to the second direction y), and it is easier to bypass the first first guide roller 21 after passing through the second guide roller 5. The third guide roller 6 corresponds to the position of the outlet 12 along the first direction x, and can guide the pole piece 4 to reach the outlet 12 after passing through the last first guide roller 21, and lead out from the outlet 12 in a preset direction (for example, parallel to the second direction y).

[0110] Figure 2 The middle inlet 11, outlet 12, second guide roller 5 and third guide roller 6 are all located in the middle position of the box body 1 along the first direction x. Optionally, they can also be arranged near the two ends of the box body 1 along the first direction. Their setting positions are determined according to the entry and exit positions of the pole pieces 4 in the upstream and downstream equipment.

[0111] This embodiment provides a second guide roller 5 and a third guide roller 6, which can guide the electrode piece 4 when it enters the box body 1 through the inlet 11 or is led out through the outlet 12, preventing the electrode piece 4 from contacting the inlet 11 or the outlet 12 to cause wear of the active material, and guides the electrode piece 4 to the first first guide roller 21 or leads it out from the last first guide roller 21 along a suitable path, and can also keep the tension on the electrode piece 4.

[0112] In some embodiments, Figure 2 As shown, the heating assembly 3 includes a plurality of heating components 3', and the plurality of heating components 3' are located between two roller groups 2 along the first direction x and are arranged at intervals along the second direction y. In the second direction y, the plurality of heating components 3' are arranged at least between every two adjacent first guide rollers 21, and the heating components 3' are configured to heat the length segments of the electrode sheet 4 located on both sides of the heating components 3' along the second direction y.

[0113] Among them, multiple heating components 3' can adopt the same structure. The heating component 3' is located between the two roller groups 2 along the first direction x, for example, it can be located in the middle area between the two roller groups 2. For one of the roller groups 2, a heating component 3' is provided between two adjacent first guide rollers 21, and for the other roller group 2, a heating component 3' is also provided between two adjacent first guide rollers 21. Further, a heating component 3' is provided between the second guide roller 5 and the two first guide rollers 21 located at the outermost ends of the two roller groups 2 and close to the second guide roller 5, and / or a heating component 3' is provided between the third guide roller 6 and the two first guide rollers 21 located at the outermost ends of the two roller groups 2 and close to the third guide roller 6.

[0114] The heating component 3' in this embodiment is located between two adjacent length segments of the pole piece 4, and the length segments on both sides can be heated simultaneously by the heating component 3'. Compared with the method in which the heating component is arranged at the top or bottom of the box to heat the pole piece on one side, the heat emitted by the heating component 3 can be fully utilized, the energy distribution of the heating component 3 is uniform, the heating time of the pole piece 4 in the box 1 is increased, and the drying efficiency of the pole piece 4 is improved.

[0115] Moreover, the distance between the heating component 3' and the pole piece 4 on both sides of the heating component 3' is relatively close, so that each heating component 3' heats different positions of the pole piece 4 evenly, thereby making the drying effect of the pole piece 4 along the extension direction consistent, thereby ensuring the process performance of the pole piece 4.

[0116] In addition, for the length section of the pole piece 4 that bypasses two adjacent first guide rollers 21, heating components 3' are provided on both sides thereof, which can heat both sides of the pole piece 4 at the same time, realize rapid drying, and improve drying efficiency. Moreover, the inside and outside of the coated active material layer can be dried at the same time to prevent the binder from floating during the drying process, so that the active material layer can have uniform composition, which is beneficial to improve the fit and bonding force between the active material layer and the current collector, thereby improving the drying effect of the active material layer.

[0117] In some embodiments, a plurality of heating components 3' may be arranged side by side along the first direction x between two adjacent first guide rollers 21. A single heating component 3' may extend along the third direction z and be installed on the side wall of the box body 1 perpendicular to the third direction z, and the heating area of ​​the heating component 3' along the third direction z may be close to the width of the pole piece 4.

[0118] This embodiment can dry a larger area of ​​the electrode 4, thereby making the drying of the electrode more uniform and improving the drying efficiency.

[0119] In some embodiments, Figure 3 As shown, the heating component 3' includes a heating element 31 and a protective cover 32, and the protective cover 32 is sleeved outside the heating element 31. For example, Figure 431 is a schematic diagram of the structure of the heating element 31 . The heating element 31 may be an infrared lamp, a heating wire or an electric heating tube, etc. The protective cover 32 may surround the heating element 31 to separate the heating element 31 from the environment outside the protective cover 32 .

[0120] Among them, for the cathode electrode, an oily solvent NMP (N-methylpyrrolidone) is used as a coating carrier, which will release NMP gas when heated at high temperature. NMP may explode at high temperature. By setting a protective cover 32, NMP gas can be prevented from directly contacting the high temperature generated by the internal heating element 31 to cause explosion, thereby improving the safety of the heating component 3', thereby extending the service life of the heating component 3' and facilitating installation. In order to completely separate the heating element 31 from the generated NMP gas, the protective cover 32 needs to have sealing performance.

[0121] For the anode plate, an aqueous solvent is used as a coating carrier, and NMP gas will not be released when heated at high temperature. The protective cover 32 is only provided to protect the heating element 31, improve the safety of the heating component 3', and prevent the heating element 31 from overheating and affecting other components in the box 1, which can increase the service life of the heating component 3' and facilitate installation. There is no excessive requirement for the sealing of the protective cover 32.

[0122] This embodiment provides a protective cover 32 for the heating element 31 to prevent the high temperature area of ​​the heating element 31 from directly heating the pole piece 4 or the components in the housing 1, so that the heating temperature is more controlled, thereby improving the safety of the operation of the heating component 3', and reliably controlling the heating temperature of the pole piece 4 within a suitable process temperature range, and preventing damage to other components in the housing 1.

[0123] In some embodiments, Figure 5 As shown, the heating element 31 is an infrared heating element, the protective cover 32 is made of a light-transmitting material, and at least one of the protective cover 32 and the infrared heating element is provided with a light-blocking layer 33 at both ends along the first direction x, so that the infrared light emitted by the infrared heating element is irradiated toward both sides along the second direction y.

[0124] For example, the infrared heating element may be an infrared lamp tube, or an infrared electric heating element may be used, which is convenient for controlling the heating temperature, and the structure and use are relatively simple. The protective cover 32 may be made of quartz material, etc., and the light-blocking layer 33 may be a gold-plated layer, etc. Since the infrared heating element achieves heating by emitting infrared light, by setting the light-blocking layer 33 at both ends of the protective cover 32 or the infrared heating element, a non-irradiated surface is formed, which can block the infrared light from being emitted toward both ends along the first direction x, and prevent the infrared light from affecting the various components of the box 1. The infrared heating element forms an irradiated surface on the two side areas where the light-blocking layer 33 is not set, so that the infrared light is only irradiated toward the length section of the pole piece 4 located on both sides of the infrared heating element.

[0125] For example, the infrared lamp tube may be in the shape of an "8", and light-blocking layers 33 are respectively arranged on the arc-shaped surfaces at both ends of the infrared lamp tube along the first direction x, and the light-blocking layers 33 at both ends are arranged oppositely. Tungsten wires 311 are arranged in both cylindrical regions of the "8"-shaped infrared lamp tube. The irradiation areas on both sides can be symmetrically arranged, each about 120°.

[0126] This embodiment provides a light-transmitting protective cover 32, and provides a light-blocking layer 33 at both ends of the protective cover 32 and at least one of the infrared heating elements along the first direction x. This not only meets the requirement that the infrared heating element irradiates infrared light toward the length sections on both sides of the pole piece 4 for heating, but also prevents the infrared light from irradiating other components in the box body 1. On the basis of ensuring the drying effect of the pole piece 4, the reliability and safety of the pole piece heating device 10 are improved.

[0127] In some embodiments, the first direction x is the height direction of the box 1. Correspondingly, the second direction y is the length direction of the box 1, which is consistent with the forward direction of the pole piece 4, and the third direction z is the width direction of the box 1, that is, Figure 2 It is a cross-sectional view of the pole piece heating device 10 in a plane perpendicular to the width direction.

[0128] Thus, the two roller groups 2 are arranged at intervals along the height direction of the box body 1, and the multiple first guide rollers 21 in each roller group 2 can be arranged at intervals along the length direction of the box body 1. The heating component 3' can extend along the width direction of the box body 1, and in order to increase the heating area, the multiple heating components 3' in each heating assembly 3 can be arranged side by side along the height direction of the box body 1.

[0129] This embodiment can make the electrode 4 present an up and down wavy shape, that is, the amplitude of the extension curve of the electrode 4 is along the height direction of the box 1, and can make the extension direction of the electrode 4 adapt to the extension direction of the electrode 4 in the two processes of the current electrode coating device 20 and the electrode drying device 30, so that the movement of the electrode 4 is smoother, and wrinkles can be prevented from being generated on the electrode 4, thereby improving the process performance of the electrode 4 after drying.

[0130] Optionally, the first direction x is the width direction of the box 1. Correspondingly, the second direction y is the length direction of the box 1, which is consistent with the forward direction of the pole piece 4, and the third direction z is the height direction of the box 1, that is, Figure 2 It is a cross-sectional view of the pole piece heating device 10 in a plane perpendicular to the height direction.

[0131] In some embodiments, Figure 2 As shown, the pole piece heating device 10 further includes a cooling assembly 7, which is disposed outside the housing 1 and downstream of the lead-out position of the pole piece 4 and is configured to cool the heated pole piece 4.

[0132] This embodiment can quickly reduce the temperature of the pole piece 4 after drying the pole piece 4 to prevent the subsequent measurement and winding process of the pole piece 4 from being affected.

[0133] In some embodiments, the cooling assembly 7 includes a cooling roller 72 configured to cool the pole piece 4 passing around it.

[0134] There may be one or more cooling rollers 72 , and the pole piece 4 is led out of the housing 1 and passes through each cooling roller 72 in sequence for cooling. A cooling liquid or gas may be passed into the cooling roller 72 .

[0135] like Figure 2 As shown, the cooling assembly 7 may also include: a cooling box 71 and a fourth guide roller 73, and a cooling roller 72 is arranged in the cooling box 71. An opening 711 may be provided on the cooling box 71, and the opening 711 is arranged opposite to the outlet 12 of the box body 1. A fourth guide roller 73 may be arranged at the opening 711, and one or more fourth guide rollers 73 may be arranged in sequence in the cooling box 71. The cooling roller 72 may be arranged downstream of all the fourth guide rollers 73. After the pole piece 4 is led out from the outlet 12, it bypasses the fourth guide roller 73 at the opening 711, and bypasses the fourth guide roller 73 and the cooling roller 72 in the cooling box 71 in sequence before being led out from the cooling box 71. The purpose of setting a plurality of fourth guide rollers 73 is to extend the extension path of the pole piece 4, increase the cooling rate, and keep the pole piece 4 at a suitable tension.

[0136] This embodiment provides a cooling roller 72 so that the pole piece 4 can be fitted with the outer surface of the cooling roller 72 to achieve cooling. Good fitting can improve the cooling effect and has low cost.

[0137] Optionally, the cooling assembly 7 may also use an air nozzle, such as a narrow and long air nozzle extending along the width direction of the pole piece 4, to achieve cooling by blowing cold air.

[0138] In some embodiments, Figure 2 As shown, the box body 1 is provided with a recovery port 13, and the electrode heating device 10 further includes a collecting component 8, which is configured to collect steam and chemical gases generated in the box body 1 during the heating process through the recovery port 13. For example, the collecting component 8 can be a fan, an adsorbent, and the like.

[0139] This embodiment takes into account that water vapor and chemical gases will be generated during the heating process of the electrode 4. During the heating process or after the heating is completed, the water vapor and chemical gases in the box body 1 are collected by the collecting component 8 through negative pressure, so that the box body 1 can maintain a dry environment, improve the drying efficiency, and prevent the chemical gas from corroding the electrode 4 or other components in the box body 1, thereby ensuring the process performance of the electrode 4 after drying and increasing the service life of the electrode heating device 10.

[0140] Combine the following Figures 1 to 5, the structure of the electrode heating device 10 of the present application is described in detail.

[0141] like Figure 1 As shown, the electrode heating device 10 is arranged downstream of the electrode drying device 30. After the electrode 4 is coated with active material in the electrode coating device 20, it enters the electrode drying device for preliminary drying, and then enters the electrode heating device 10 for heating.

[0142] like Figure 2 As shown, the pole piece heating device 10 comprises: a box body 1, two roller groups 2 and a heating assembly. The two roller groups 2 are installed in the box body 1 at intervals along the first direction x (the height direction of the box body 1), and each roller group 2 comprises a plurality of first guide rollers 21 arranged at intervals along the second direction y (the length direction of the box body 1). The pole piece 4 alternately passes around all the first guide rollers 21 in the two roller groups 2 in turn to form a wave shape with an amplitude along the first direction x.

[0143] An inlet 11 and an outlet 12 are respectively arranged on the two side walls 1A of the box body 1 perpendicular to the second direction y. A second guide roller 5 is arranged at the inlet 11, and a third guide roller 6 is arranged at the outlet 12. After the pole piece 4 enters from the inlet 11, it passes through the second guide roller 5, all the first guide rollers 21 and the third guide roller 6 in sequence, and then is led out from the outlet 12. The pole piece 4 after being led out enters the cooling assembly 7 for cooling, so as to facilitate subsequent measurement and winding. The box body 1 has a top wall 1B and a bottom wall 1C perpendicular to the first direction x, and the power component 91 and the recovery port 13 can be arranged on the top wall 1B.

[0144] The heating assembly 3 is installed in the box body 1. The heating assembly 3 may include multiple heating components 3'. The portion between each two adjacent first guide rollers 21 on the extension path of the pole piece 4 can be called a length segment, and the portion between the first guide roller 21 and the second guide roller 5 and the portion between the first guide roller 21 and the third guide roller 6 can be called length segments. Then, a heating component 3' can be set between each two adjacent length segments of the pole piece 4 along the second direction y, so that the heating components 3' can be used to heat the length segments on both sides at the same time to improve the drying efficiency. Furthermore, multiple heating components 3' can be set between each two adjacent length segments, and multiple heating components 3' can be arranged side by side along the first direction x to expand the heating range and improve the heating uniformity. The heating component 3' can extend along the third direction z to achieve heating of the entire width area of ​​the pole piece 4.

[0145] like Figure 3 As shown, the heating component 3' comprises a heating element 31 and a protective cover 32. The protective cover 32 is sleeved outside the heating element 31. The heating element 31 may be an infrared lamp. The protective cover 32 may be provided with a first opening 321 and a second opening 322 for introducing cold air to ensure positive pressure inside the protective cover 32. The protective cover 32 is provided with a flange 323 for mounting the heating component 3' on the box body 1.

[0146] like Figure 4 As shown, it is a schematic diagram of the side structure of the heating element 31. Two lead wires 34 are provided at one end of the heating element 31 extending out of the protective cover 32. A tungsten wire 311 is provided in the heating element 31. The outside of the tungsten wire 311 is wrapped with ceramic non-metallic material to play an insulating and protective role.

[0147] like Figure 5 , which is a schematic diagram of the end structure of the heating element 31. The heating element 31 is an infrared heating element, such as an infrared lamp tube, and the protective cover 32 is made of a light-transmitting material. The infrared lamp tube can be in an "8" shape, and light-blocking layers 33 are respectively arranged on the arc surfaces at both ends of the infrared heating element along the first direction x, and the light-blocking layers 33 at both ends are arranged oppositely. Tungsten wires 311 are arranged in both cylindrical regions of the "8"-shaped infrared lamp tube.

[0148] By setting a light-blocking layer 33 at both ends of the infrared heating element to form a non-irradiated surface, it is possible to block the infrared light from being emitted toward both ends along the first direction x, thereby preventing the infrared light from affecting the various components of the box body 1. The infrared heating element forms an irradiated surface in the two side areas where the light-blocking layer 33 is not set, so that the infrared light is only irradiated toward the length section of the pole piece 4 located on both sides of the infrared heating element.

[0149] Optionally, since the working temperature of the heating component 3' is relatively high, cold air may be introduced for cooling. In addition, a temperature sensor may be provided on the surface of the heating component 3' to detect the working temperature of the heating component 3', and an alarm may be given when the working temperature exceeds a preset temperature, and heating may be stopped by power off to meet explosion-proof requirements. By measuring the surface temperature of the heating component 3', the working temperature of the heating component 3' may be obtained more accurately.

[0150] Secondly, the present application provides a method for producing a pole piece. In some embodiments, Figure 6 As shown, the pole piece production method comprises:

[0151] S101, coating the active material in the electrode 4 by the electrode coating device 20;

[0152] S102, baking the coated electrode 4 by the electrode drying device 30; and

[0153] S103 , reheating the baked electrode 4 by the electrode heating device 10 of the above embodiment.

[0154] Among them, S101 to S103 are performed sequentially. This electrode production method uses the electrode heating device 10 disposed downstream of the electrode drying device 30 to preliminarily dry the electrode 4, and then enters the electrode heating device 10 for secondary drying, which can optimize the drying effect of the electrode 4, shorten the residence time of the electrode 4 in the electrode drying device 30, and increase the movement speed of the electrode 4, thereby increasing the coating rate of the electrode 4.

[0155] In some embodiments, the pole piece 4 is in motion during the coating, baking and reheating process of the pole piece 4. This method can make the coating process of the pole piece 4 more continuous, the coating of the active material on the substrate more uniform, and improve the coating efficiency.

[0156] 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 it. 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 of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A pole piece heating device (10), comprising: Box (1); Two roller groups (2) are installed in the box (1), the two roller groups (2) are arranged at intervals along a first direction (x), and each roller group (2) comprises a plurality of first guide rollers (21) arranged at intervals along a second direction (y), so that the pole piece (4) can alternately pass around all the first guide rollers (21) in the two roller groups (2) in sequence, and the second direction (y) is perpendicular to the first direction (x); and A heating component (3) is installed in the box (1) and is configured to heat the electrode (4) after coating; The heating assembly (3) comprises a plurality of heating components (3'), the plurality of heating components (3') being located between two roller groups (2) along a first direction (x) and being arranged at intervals along a second direction (y), and the plurality of heating components (3') being arranged at least between every two adjacent first guide rollers (21) in the second direction (y), and the heating components (3') being configured to heat a length section of the pole piece (4) located on both sides of the heating component (3') along the second direction (y); The heating component (3') comprises a heating element (31) and a protective cover (32), wherein the protective cover (32) is sleeved outside the heating element (31), the heating element (31) is an infrared heating element, the protective cover (32) is made of a light-transmitting material, and at least one of the protective cover (32) and the infrared heating element is provided with a light-blocking layer (33) at both ends along the first direction (x), so that the infrared light emitted by the infrared heating element is irradiated toward both sides along the second direction (y).

2. The pole piece heating device (10) according to claim 1, wherein: The plurality of first guide rollers (21) of each of the two roller groups (2) are staggered along the second direction (y).

3. The pole piece heating device (10) according to claim 1, wherein: The axis of the first guide roller (21) is arranged along a third direction (z), and the third direction (z) is perpendicular to the first direction (x) and the second direction (y).

4. The pole piece heating device (10) according to claim 1, wherein: The first guide roller (21) is rotatably arranged around its own axis, and the first guide rollers (21) in the two roller groups (2) rotate in opposite directions.

5. The pole piece heating device (10) according to any one of claims 1 to 4, wherein: The box body (1) is provided with an inlet (11) and an outlet (12), and the inlet (11) and the outlet (12) are respectively located on two side walls (1A) of the box body (1) perpendicular to the second direction (y); The pole piece heating device (10) further comprises: a second guide roller (5), located between the two roller groups (2) and the inlet (11) along the second direction (y), and corresponding to the position of the inlet (11) along the first direction (x), and configured to provide guidance for the pole piece (4) in a length section from the inlet (11) to the first of the first guide rollers (21); and A third guide roller (6) is located between the two roller groups (2) and the outlet (12) along the second direction (y), and corresponds to the position of the outlet (12) along the first direction (x), and is configured to provide guidance for the pole piece (4) in a length section from the last of the first guide rollers (21) to the outlet (12).

6. The pole piece heating device (10) according to claim 1, wherein: A plurality of the heating components (3') may be arranged side by side along the first direction (x) between two adjacent first guide rollers (21).

7. The pole piece heating device (10) according to any one of claims 1 to 4, wherein: The first direction (x) is the height direction of the box (1).

8. The pole piece heating device (10) according to any one of claims 1 to 4, further comprising a cooling assembly (7), arranged outside the box (1) and configured to cool the pole piece (4) after being heated.

9. The pole piece heating device (10) according to claim 8, wherein: The cooling assembly (7) comprises a cooling roller (72) configured to cool the pole piece (4) passing around the cooling roller.

10. The pole piece heating device (10) according to any one of claims 1 to 4, wherein: The box body (1) is provided with a recovery port (13), and the electrode heating device (10) further comprises a collecting component (8) configured to collect steam and chemical gases generated in the box body (1) during the heating process through the recovery port (13).

11. A pole piece production system, comprising: A pole piece coating device (20) configured to coat the active material in the pole piece (4); A pole piece drying device (30), disposed downstream of the pole piece coating device (20), configured to bake the coated pole piece (4); and The electrode heating device (10) according to any one of claims 1 to 10 is arranged downstream of the electrode drying device (30) and is configured to reheat the baked electrode (4).

12. A method for producing a pole piece, comprising: coating the active material in the pole piece (4) by means of a pole piece coating device (20); Baking the coated pole piece (4) by means of a pole piece drying device (30); and The baked pole piece (4) is reheated by the pole piece heating device (10) according to any one of claims 1 to 10.

13. The pole piece production method according to claim 12, wherein: During the process of coating, baking and reheating the pole piece (4), the pole piece (4) is in a moving state.

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