Patent Description:
Achieving energy conservation and emission reduction is the key to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages in energy conservation and being environmentally friendly. For the electric vehicles, the battery technology is an important factor to their development.

During manufacturing batteries, the production efficiency of the batteries is a nonnegligible issue. Therefore, how to increase the production efficiency of the batteries is an urgent technical problem to be solved in the battery technology.

Embodiments of D1(<CIT>) discloses drying system includes multiple ovens. To ensure that the humidity and temperature of the electrode at the outlet of the last section of the oven reach the target value, the dynamic adjustment of the fan air volume and heater heating temperature is gradually completed forward based on the target temperature and humidity value, so that the humidity and temperature of the electrode at the outlet of the last section of the oven reach the target value. After the working conditions change, compare the humidity and temperature values detected by the current oven with the initial reference value of the oven. If the detected values are inconsistent with the initial reference value, the controller will issue commands to control the air volume and/or hot air temperature to the frequency converter and heater of the previous oven or the second oven ahead of the current oven.

The embodiments of D2(<CIT>) discloses discloses drying section includes a drying furnace Z1 and a drying furnace Z2, and it is preferable to set the temperature of the hot air in the drying furnace Z1 to be lower than that in the drying furnace Z2. Alternatively, the drying section includes three drying furnaces, where hot air is blown in a parallel direction in the middle of the three drying furnaces (i.e. drying furnace Z2), and hot air is blown to the coating film in the upstream drying furnace Z1 and downstream drying furnace Z3.

The embodiments of D3(<CIT>) discloses that the first section of oven <NUM>, the second section of oven <NUM>, and the third section of oven <NUM> are sequentially arranged in the direction of electrode movement, and the wind speed of the second section of oven <NUM> is greater than that of the first section of oven <NUM>, while the wind speed of the third section of oven <NUM> is greater than that of the second section of oven <NUM>.

The scope of the invention is defined by the appended set of claims.

In order to more clearly describe the technical solutions of the embodiments of the present application, the accompanying drawings required in the embodiments will be described briefly below. It should be understood that the following accompanying drawings illustrate only some embodiments of the present application and therefore should not be construed as a limitation on the scope thereof. For those of ordinary skill in the art, other relevant accompanying drawings can also be obtained from these accompanying drawings without any creative effort.

List of reference signs: <NUM> - Drying device; <NUM>- First oven section; <NUM> - First tuyere; <NUM> - Second oven section; <NUM> - Second tuyere; <NUM>- Third oven section; <NUM> - Third tuyere; <NUM> - Roller; <NUM> - Air outlet face structure; <NUM> - Boosting part; <NUM> - First slit; <NUM> - First frame; <NUM> - First connecting portion; <NUM> - Air outlet part; <NUM> - Second slit; <NUM> - Second frame; <NUM> - Second connecting portion.

In order to make objects, technical solutions and advantages of embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings for the embodiments of the present application. Obviously, the described embodiments are some of, rather than all of, the embodiments of the present application. All the other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without any creative effort shall fall within the scope of protection of the present application.

Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are merely for the purpose of describing specific embodiments, but are not intended to limit the present application. The terms "comprising" and "having" and any variations thereof in the description and the claims of the present application as well as the brief description of the accompanying drawings described above are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and the claims of the present application as well as the foregoing accompanying drawings are used to distinguish between different objects, rather than describing a specific order or a primary-secondary relationship.

The phrase "embodiments" referred to in the present application means that the descriptions of specific features, structures, and characteristics in combination with the embodiments are included in at least one embodiment of the present application. The phrase at various locations in the description does not necessarily refer to the same embodiment, or an independent or alternative embodiment exclusive of another embodiment.

In the description of the present application, it should be noted that, the terms "mount", "connected", "connect", or "attach" should be interpreted in a broad sense unless explicitly defined and limited otherwise. For example, they may be a fixed connection, a detachable connection, or an integral connection; or may be a direct connection, an indirect connection by means of an intermediate medium, or internal communication between two elements. For those of ordinary skills in the art, the specific meaning of the foregoing terms in the present application may be understood according to specific circumstances.

The term "and/or" in the present application is merely a description of the associated relationship of associated objects, representing that three relationships may exist, for example, A and/or B, may be expressed as: presence of A, both A and B, or B. In addition, the character "/" in the present application generally indicates that the associated objects before and after the character are in an "or" relation.

In the embodiments of the present application, the same reference numerals denote the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the dimensions, such as thickness, length and width, of the various components in the embodiments of the present application illustrated in the accompanying drawings, as well as the dimensions, such as an overall thickness, length and width, of an integrated device are merely illustrative and should not be construed to limit the present application in any way.

"A plurality of" appearing in the present application means two or more (including two).

In the present application, a 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 by the embodiments of the present application.

A battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module, a battery pack, etc. The battery generally includes a case for enclosing one or more battery cells. The case can prevent liquid or other foreign matters from affecting charging or discharging of a battery monomer.

The core member of the battery that can implement a repeated charge and discharge function is an electrode assembly in the battery cell. The electrode assembly comprises an electrode plate and a separator, the electrode plate including a positive electrode plate and a negative electrode plate. The separator is usually disposed between the positive electrode plate and the negative electrode plate for insulation of the positive electrode plate from the negative electrode plate, and the separator may be made of polypropylene (PP), polyethylene (PE), etc. The battery cell operates mainly by relying on movements of metal ions between the positive electrode plate and the negative electrode plate. The electrode plate comprises a current collector and an active material layer. The current collector has a coating area coated with an active material layer and an uncoated area not coated with an active material layer in a width direction of the electrode plate. Tabs are cut on the current collector not coated with the active material layer, and the tabs realize the charge and discharge of the electrode assembly. The current collector can be metal foil, such as copper foil, aluminum foil, and the like. A process for preparation of the electrode plate comprises a coating procedure in which a stirred slurry (i.e., the active material in the form of a slurry) is evenly applied on the current collector to form a film layer, and a drying procedure in which the film layer is dried to be a dry film layer so as to form the active material layer.

At present, from the development of the market situation, electric vehicles have become an important part of the sustainable development of the automotive industry. The battery provides energy for the running of a vehicle body and the operations of various electrical components in the vehicle body. For the electric vehicles, the battery technology is an important factor to their development. In the development of battery technology, how to increase the production efficiency of batteries is an urgent technical problem to be solved in the battery technology.

During the manufacturing of the battery, the efficiency of the drying procedure is one of the key factors affecting the production efficiency of the battery. The inventors have found that an airflow at a fixed air speed is usually used to dry the electrode plate in an existing drying procedure. When the slurry is just applied on the current collector to form a film layer, the film layer is unstable and is easily damaged by the airflow. In order to prevent the film layer from being damaged, the current collector is often dried at a lower fixed air speed, but the lower air speed impairs the drying efficiency of the electrode plate, which in turn influences the production efficiency of the battery.

Based on the above consideration, in order to increase the drying efficiency of the electrode plate to increase the production efficiency of the battery, the inventor has designed a drying device after in-depth studies, the drying device comprising: a first oven section; a second oven section; and a third oven section, the first oven section, the second oven section and the third oven section being arranged sequentially in a movement direction of the electrode plate, wherein the second oven section has a larger air outlet area than the first oven section, and the first oven section has a larger air outlet area than the third oven section, such that the air speed of the first oven section is greater than that of the second oven section, and the air speed of the third oven section is greater than that of the first oven section.

In the case of the same air source, that is, under the condition of a certain total volume of air, the air speed of each of the oven sections can be adjusted by adjusting the air outlet area of the oven section, thus providing different drying effects for the electrode plate at different times. The first oven section provides an airflow at a high air speed to quickly preheat a film layer on the electrode plate. The wet film layer (at this moment, the film layer is a wet film layer) can be quickly preheated by the airflow at the high air speed with no damages to the film layer on the surface of the material. The second oven section provides an airflow at a low air speed to the electrode plate to provide slow evaporation for the electrode plate. By means of the airflow at the low air speed, a solvent in the wet film layer can be evaporated and damages to the film layer caused by an excessive air speed can be prevented. The third oven section is an oven section with the highest air speed among the three oven sections. Since the film layer on the electrode plate has been formed after the evaporation in the second oven section, a high-speed airflow is provided to the electrode plate, which can quickly dry the electrode plate, such that the wet film layer is formed into a dry film layer, thereby increasing the drying efficiency of the electrode plate and increasing the production efficiency of the batteries. To this end, compared with a scheme of drying the electrode plate at a fixed lower air speed, this scheme provides airflows at different air speeds to the electrode plate according to different states of the film layer, which can increase the drying efficiency while ensuring the drying quality, thereby increasing the production efficiency of the batteries.

The drying device disclosed in the embodiments of the present application can be used, but not limited to, in an electrode plate manufacturing apparatus or other apparatuses that need to dry materials. The material mentioned in the embodiments of the present application may refer to an electrode plate, or other materials that have a film layer on its surface and need to be dried. An electrode plate is used as an example of the material for illustration below.

The technical solution described in the embodiments of the present application is applicable to an electrode plate manufacturing apparatus. The electrode plate manufacturing apparatus may refer to an apparatus that dries a current collector coated with an active material, or refer to an apparatus including a coating device and a drying device. The coating device is an apparatus that can evenly apply the active material to the current collector.

Referring to <FIG> is a schematic diagram of a drying device <NUM> according to some embodiments of the present application. In <FIG>, an electrode plate is denoted by the reference sign A. The drying device <NUM> for drying an electrode plate comprises a first oven section <NUM>, a second oven section <NUM> and a third oven section <NUM>. The first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are arranged sequentially in a movement direction of a material. The second oven section <NUM> has a larger air outlet area than the first oven section <NUM>, and the first oven section <NUM> has a larger air outlet area than the third oven section <NUM>, such that the air speed of the first oven section <NUM> is greater than that of the second oven section <NUM>, and the air speed of the third oven section <NUM> is greater than that of the first oven section <NUM>.

The first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> can be parts that provide airflows to the electrode plate. Air outlet faces of the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> face the electrode plate, such that the airflows from the respective air outlet faces are blown to the surface of the electrode plate, wherein the airflows may be hot airflows. The first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are supplied with air from the same air source. In other words, an oven device comprises or is connected to an air supply unit which supplies air to the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> simultaneously such that the total volume of air of the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> is fixed. It should be explained that since the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are supplied with air from the same air source, the air outlet speed of each oven section can be adjusted based on its respective air outlet area to ensure a controllable air outlet speed of the oven section.

Based on the formula that a volume of air is equal to an air speed multiplied by an air outlet area, if the total volume of air is fixed, controlling the air outlet area of each oven section can control the air speed of the oven section.

In some embodiments, referring to <FIG>, the electrode plate is supported by rollers <NUM> on a side away from the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM>, so as to realize the feeding movement of the electrode plate.

According to the technical solution of the embodiment of the present application, the material moves and passes through the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> sequentially. The first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> each provide an airflow for the material to dry a film layer on a surface of the material. Since the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are supplied with air from the same air source, by adjusting respective air outlet areas of the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM>, each oven section is allowed to provide an airflow at a different air speed to the material to achieve different drying effects.

The first oven section <NUM> provides an airflow at a high air speed to quickly preheat the electrode plate. At this moment, the film layer on the surface of the material is wet, and the wet film layer can be quickly preheated by the airflow at the high air speed with no damages to the film layer on the surface of the material to reduce the flowability of the film layer and improve the uniformity of the thickness of the film layer. The second oven section <NUM> provides an airflow at a low air speed to the electrode plate, which can provide slow evaporation for the electrode plate. By means of the airflow at the low air speed, a solvent in the wet film layer can be evaporated and damages to the film layer caused by an excessive air speed can be prevented (an excessive air speed may result in excessively quick drying of the surface of the film layer, and vapor may flow and break through a dry film on the top to cause cracks in internal drying). The third oven section <NUM> is an oven section with the highest air speed among the three oven sections. Since the film layer on the electrode plate has been formed through the second oven section <NUM>, a high-speed airflow is provided to the electrode plate, which can quickly dry the electrode plate, such that the wet film layer is formed into a dry film layer, thereby increasing the drying efficiency of the electrode plate and increasing the production efficiency of the batteries. To this end, compared with a scheme of drying the electrode plate at a fixed lower air speed, this scheme provides airflows at different air speeds to the electrode plate according to different states of the film layer, which can increase the drying efficiency while ensuring the drying quality, thereby increasing the production efficiency of the batteries.

In some embodiments according to the present application, the first oven section <NUM> has an air speed of less than <NUM>/s, the second oven section <NUM> has an air speed of less than <NUM>/s, and the third oven section <NUM> has an air speed of <NUM>-<NUM>/s.

The first oven section <NUM> having an air speed of less than <NUM>/s means that the maximum speed at which the first oven section <NUM> blows an airflow to the electrode plate is less than <NUM>/s and greater than the air speed of the second oven section <NUM>, for example, <NUM>/s. The second oven section <NUM> having an air speed of less than <NUM>/s means that the speed at which the second oven section <NUM> blows an airflow to the electrode plate is less than <NUM>/s, for example, <NUM>/s. The third oven section <NUM> having an air speed of <NUM>-<NUM>/s means that the speed at which the third oven section <NUM> blows an airflow to the electrode plate is between <NUM>/s and <NUM>/s, for example, <NUM>/s, <NUM>/s, <NUM>/s s or <NUM>/s, etc..

The air speeds of the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are defined, such that it is possible to increase the drying efficiency of the electrode plate as much as possible while ensuring that the film layer of the electrode plate is not damaged, thereby increasing the production efficiency of the batteries while ensuring the quality of the batteries.

According to the present invention, referring to <FIG>, the first oven section <NUM> has a plurality of first tuyeres <NUM>, the second oven section <NUM> has a plurality of second tuyeres <NUM>, and the third oven section <NUM> has a plurality of third tuyeres <NUM>. Both of the first tuyeres <NUM> and the second tuyeres <NUM> have a larger air outlet area than the third tuyeres <NUM>.

The tuyeres are components that can rectify the airflows, such that the airflow blown out by the oven can effectively act on the electrode plate, and the sum of the air outlet areas of all the tuyeres in the oven is equal to the air outlet area of the oven. Optionally, the oven comprises an oven body and a plurality of tuyeres, wherein the oven body has an air port in which the tuyeres are provided, and the oven body is supplied with air from an air source (such as the air supply unit), such that the airflow in the oven body is provided by each tuyere.

Provisions of the plurality of the first tuyeres <NUM> in the first oven section <NUM>, the plurality of second tuyeres <NUM> in the second oven section <NUM>, and the plurality of third tuyeres <NUM> in the third oven section <NUM> can ensure the uniformity of air outlet of each oven section and thus the drying effect of each oven section. In addition, the air outlet area of the third tuyeres <NUM> are set to be smaller than the air outlet areas of the first tuyeres <NUM> and the second tuyeres <NUM> in such a way that it can effectively ensure that the third oven section <NUM> provides an airflow at a higher air speed to the electrode plate than the first oven section <NUM> and the second oven section to ensure quick drying of the electrode plate.

In some embodiments according to the present application, referring to <FIG> is a schematic diagram of the second oven section according to some embodiments of the present application. In the movement direction of the electrode plate, the number of tuyeres of each of the oven sections is not less than <NUM> per <NUM>, and the center-to-center distance between two adjacent tuyeres is not greater than <NUM>.

In <FIG>, the center-to-center distance between two tuyeres is indicated by an arrow plus a reference sign B.

Each oven section refers to any one of the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM>. In the first oven section <NUM>, the tuyeres are the first tuyeres <NUM>. In the second oven section <NUM>, the tuyeres are the second tuyeres <NUM>. In the third oven section <NUM>, the tuyeres are the third tuyeres <NUM>.

Each oven section extends along the movement direction of the electrode plate, and is arranged with a plurality of tuyeres in an extension direction thereof to ensure the drying effect of the electrode plate. In order to improve the drying effect of the electrode plate, with every <NUM> as a unit, at least <NUM> tuyeres are arranged in each unit. The value of the center-to-center distance between two adjacent tuyeres affects the presence of an airflow in an area between the two tuyeres, and determines whether the electrode plate can be effectively dried in the area. For this, the center-to-center distance between the tuyeres is set to be not greater than <NUM>, which can improve the drying effect of the electrode plate.

In each oven section, the number of tuyeres provided per <NUM> is not less than <NUM>, and the center-to-center distance between two adjacent tuyeres is not greater than <NUM>, which can ensure the uniformity of the air outlet of the oven section and ensure that the airflow can completely cover the electrode plate to ensure the drying quality and efficiency of the electrode plate.

Optionally, each oven section may comprise a plurality of segments which each may be <NUM> in length. In one embodiment, each oven section comprises three segments, and each oven section has a length of <NUM>. As an example, the first oven section <NUM> comprises three segments, and the first oven section <NUM> has a total length of <NUM>. The second oven section <NUM> comprises three sections, and the second oven section <NUM> has a total length of <NUM>. The third oven section <NUM> comprises three segments, and the third oven section <NUM> has a total length of <NUM>.

In some embodiments according to the present application, the air outlet area of the first oven section <NUM> is not less than <NUM>,<NUM><NUM>/<NUM>; the air outlet area of the second oven section <NUM> is not less than <NUM>,<NUM><NUM>/<NUM>; and the air outlet area of the third oven section <NUM> is not less than <NUM>,<NUM><NUM>/<NUM>.

Taking <NUM> as a unit, the first oven section <NUM> has an air outlet area of at least <NUM>,<NUM><NUM> per <NUM> in its extension direction (if less than <NUM>,<NUM><NUM>, it will cause the air outlet speed of the first oven section <NUM> to be greater than <NUM>/s, so the air flow speed is too high, resulting in a large force acting on the film layer and causing damages to the surface of the film layer), for example, the first oven section <NUM> has an air outlet area of <NUM>,<NUM><NUM> per <NUM> in other extension directions. The second oven section <NUM> has an air outlet area of at least <NUM>,<NUM><NUM> per <NUM> in its extension direction (if less than <NUM>,<NUM><NUM>, it will cause the air outlet speed of the second oven section <NUM> to be greater than <NUM>/s, causing damages to the surface of the film layer), for example, the second oven section <NUM> has an air outlet area of <NUM>,<NUM><NUM> per <NUM> in other extension directions. The third oven section <NUM> has an air outlet area of at least <NUM>,<NUM><NUM> per <NUM> in its extension direction (if less than <NUM>,<NUM> mm2, it will cause the air outlet speed of the third oven section <NUM> to be greater than <NUM>/s, so the air flow speed is too high, resulting in a large force acting on the film layer and causing damages to the surface of the film layer), for example, the third oven section <NUM> has an air outlet area of <NUM>,<NUM> mm2 per <NUM> in other extension directions.

After defining the relative size of the air outlet area of each oven section, a minimum specific value of the air outlet area of each oven section is defined, and the air outlet area of the tuyeres can be calculated in the case of the minimum number of tuyeres, and thus the practicability of this scheme is improved to ensure that the drying device <NUM> can complete the drying operation smoothly and efficiently.

In some embodiments according to the present application, the volume of air of the first oven section <NUM> accounts for <NUM>-<NUM>% of the total volume of air of the drying device <NUM>, the volume of air of the second oven section <NUM> accounts for <NUM>-<NUM>% of the total volume of air of the drying device <NUM>, and the volume of air of the third oven section <NUM> accounts for <NUM>-<NUM>% of the total volume of air of the drying device <NUM>.

The percentage of the volume of air of the oven section accounting for the total volume of air of the drying device <NUM> means the distribution ratio of the volume of air, that is, the distribution ratio of the volume of air of the first oven section <NUM> is between <NUM>-<NUM>%, the distribution ratio of the volume of air of the second oven section <NUM> is between <NUM>-<NUM>%, and the distribution ratio of the volume of air of the third oven section <NUM> is between <NUM>-<NUM>%. The above-mentioned distribution ratios of the volume of air allow the air speed of the first oven section <NUM> to be less than <NUM>/s, the air speed of the second oven section <NUM> to be less than <NUM>/s, the air speed of the third oven section <NUM> to be between <NUM>-<NUM>/s. In the case of the numerical value of the total volume of air of <NUM>, with the distribution ratio of the volume of air of the first oven section <NUM> being <NUM>%, the distribution ratio of the volume of air of the second oven section <NUM> being <NUM>%, and the distribution ratio of the volume of air of the third oven section <NUM> being <NUM>% as an example, the numerical value of the volume of air of the first oven section <NUM> is about <NUM>, the numerical value of the volume of air of the second oven section <NUM> is about <NUM>, and the numerical value of the volume of air of the third oven section <NUM> is about <NUM>. The volume of air can be expressed in m<NUM>/h.

Since the first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are supplied with air from the same air source, by limiting the ratio of the volume of air of each oven section to the total volume of air, the air source provides a respective volume of air corresponding to the numerical value to each oven section. In combination with the air outlet area of each of the oven sections, the oven section is allowed to provide an airflow at a different air speed to achieve different drying effects, increasing the drying efficiency of the material while ensuring no damages to the film layer.

According to the present invention, referring to <FIG> and <FIG>, <FIG> is a perspective view of an air outlet face structure according to some embodiments of the present application, and <FIG> is a cross-sectional view of an air outlet face structure according to some embodiments of the present application.

The first tuyeres <NUM> and the second tuyeres <NUM> each comprise an air outlet face structure <NUM>, and the air outlet face structure <NUM> comprises a boosting part <NUM> and an air outlet part <NUM> which are superposed in an air outlet direction with a gap therebetween; and the boosting part <NUM> is formed with a plurality of first slits <NUM> at intervals, and the air outlet part <NUM> is formed with a plurality of second slits <NUM>, the first slits <NUM> being staggered with the second slits <NUM>.

The air outlet face structure <NUM> refers to a structure for blowing out an airflow, and the air outlet face structure <NUM> faces the electrode plate, such that the airflow flows to the electrode plate to dry the electrode plate. The boosting part <NUM> is a part arranged on a side of the air outlet part <NUM> away from the electrode plate. The first slits <NUM> on the boosting part <NUM> allow the airflow to pass through, so as to increase the pressure of the airflow and make the airflow flow to the second slits <NUM>. The air outlet part <NUM> is a part facing the electrode plate, and the airflow is blown out from the second slits <NUM> to act on the electrode plate. The sum of the air outlet areas of the second slits <NUM> on the air outlet part <NUM> is equal to the air outlet area of the tuyeres (the first tuyeres <NUM> or the second tuyeres <NUM>).

The cross-sectional area of the second slits <NUM> of the first tuyeres <NUM> may be smaller than the cross-sectional area of the second slits <NUM> of the second tuyeres <NUM>, such that the air outlet area of the first tuyeres <NUM> is smaller than that of the second tuyeres <NUM>, and thus the air outlet speed of the first oven section <NUM> is greater than that of the second oven section <NUM>. Alternatively, when the cross-sectional area of the second slits <NUM> of the first tuyeres <NUM> is equal to the cross-sectional area of the second slits <NUM> of the second tuyeres <NUM>, the number of the second slits <NUM> of the first tuyeres <NUM> can be less than the number of the second slits <NUM> of the second tuyeres <NUM>, such that the air outlet area of the first tuyeres <NUM> is smaller than the air outlet area of the second tuyeres <NUM>, and thus the air outlet speed of the first oven section <NUM> is greater than that of the second oven section <NUM>.

The first tuyeres <NUM> and the second tuyeres <NUM> each comprise an air outlet face structure <NUM>, and the air outlet face structure <NUM> has the advantages of a simple structure and being easy to manufacture, which can effectively reduce the manufacturing cost of the drying device <NUM>. With the provision of the boosting part <NUM> and the air outlet part <NUM>, the airflow passes through the first slits <NUM>, the gap between the boosting part <NUM> and the air outlet part <NUM>, and is ejected from the second slits <NUM>, which can improve the uniformity of the air outlet of the tuyeres, prevent damages to the film layer of the electrode plate due to turbulences, and ensure the drying effect of the material.

Optionally, the structure of the third tuyeres <NUM> may be identical to that of tuyeres in an existing drying device or an existing oven.

According to the present invention, as shown in <FIG> and <FIG>, the boosting part <NUM> comprises a first frame <NUM> and a plurality of first connecting portions <NUM> arranged in the first frame <NUM>, each of the first connecting portions <NUM> is connected to the first frame <NUM> at two ends, and the first slits <NUM> are formed between two adjacent ones of the first connecting portions <NUM>; and the air outlet part <NUM> comprises a second frame <NUM> and a plurality of second connecting portions <NUM> arranged in the second frame <NUM>, each of the second connecting portions <NUM> is connected to the second frame <NUM> at two ends, and the second slits <NUM> are formed between two adjacent ones of the second connecting portions <NUM>.

The first frame <NUM> comprises a plurality of walls which are sequentially connected to have a form of a frame. The first connecting portions <NUM> are parts disposed in the first frame <NUM>, the first connecting portions <NUM> are connected to an inner wall of the first frame <NUM>, and a plurality of first connecting portions <NUM> are arranged at intervals to form the plurality of first slits <NUM>. The second frame <NUM> comprises a plurality of walls enclosing a frame. The second connecting portions <NUM> are parts disposed in the second frame <NUM>, the second connecting portions <NUM> are connected to an inner wall of the second frame <NUM>, and the plurality of second connecting portions <NUM> are arranged at intervals to form the plurality of second slits <NUM>.

With respect to <FIG>, the first connecting portions <NUM> are located at one end of the first frame <NUM>, a chamber is formed between the first connecting portions <NUM> and the other end of the first frame <NUM>, and the size of the second frame <NUM> is smaller than that of the first frame <NUM>, such that the second frame <NUM> can be placed in the chamber and a lateral wall of a wall of the second frame <NUM> is in contact with the inner wall of the first frame <NUM>, and an end surface of the wall of the second frame <NUM> facing the first connecting portions <NUM> abuts against the first connecting portions <NUM>. The second connecting portions <NUM> are disposed in the second frame <NUM>, and have a certain distance from the end surface of the second frame <NUM> facing the first connecting portions <NUM>, such that when the second frame <NUM> is placed in the first frame <NUM>, a gap is formed between the first connecting portions <NUM> and the second connecting portions <NUM> for an airflow to pass through.

The boosting part <NUM> has a simple structure and is easy to manufacture, and the plurality of first connecting portions <NUM> are arranged at intervals in the first frame <NUM> to form the first slits <NUM>, which effectively reduces the manufacturing difficulty of the boosting part <NUM>. The air outlet part <NUM> has a simple structure and is easy to manufacture. The plurality of second connecting portions <NUM> are arranged at intervals in the second frame <NUM> to directly form the second slits <NUM>, which can effectively reduce the manufacturing difficulty of the boosting part <NUM>.

Optionally, in the first tuyeres <NUM>, the air outlet area of the air outlet part <NUM> accounts for <NUM>-<NUM>% of the total area of the air outlet part <NUM>, the widths of the first slits <NUM> and the second slits <NUM> are between <NUM>-<NUM>, the number of the first slits <NUM> and the number of the second slits <NUM> are between <NUM>-<NUM> respectively, and the total air outlet area of the air outlet part <NUM> is not less than <NUM>,<NUM><NUM>. In the second tuyeres <NUM>, the air outlet area of the air outlet part <NUM> accounts for <NUM>-<NUM>% of the total area of the air outlet part <NUM>, the widths of the first slits <NUM> and the second slits <NUM> are between <NUM>-<NUM>, the numbers of the first slit <NUM> and the number of the second slits <NUM> are between <NUM>-<NUM> respectively, the total air outlet area of the air outlet part <NUM> is not less than <NUM>,<NUM><NUM>, and the gap between the boosting part <NUM> and the air outlet part <NUM> is between <NUM>-<NUM>.

Optionally, the cross sections of the first connecting portions <NUM> and the second connecting portions <NUM> may be square, such that the first slits <NUM> and the second slits <NUM> are strip-shaped, so as to ensure the uniformity of air outlet.

In some embodiments according to the present application, the first connecting portions <NUM> and/or the second connecting portions <NUM> are hollow structures.

A hollow structure refers to a component having a cavity therein. The interior of the hollow structure is configured as a cavity to enable to effectively reduce the mass and used materials of the component. The first connecting portions <NUM> and/or the second connecting portions <NUM> being hollow structures means that the first connecting portions <NUM> are hollow structure, the second connecting portions <NUM> are hollow structures, or both the first connecting portions <NUM> and the second connecting portions <NUM> are hollow structures.

The first connecting portions <NUM> and/or the second connecting portions <NUM> are configured as hollow structures, such that the mass of the first tuyeres <NUM> and the second tuyeres <NUM> can be effectively reduced, and the material cost of the first tuyeres <NUM> and the second tuyeres <NUM> can be saved.

Optionally, the first connecting portions <NUM> and/or the second connecting portions <NUM> may be rectangular tubes (square tubes) of materials which are not limited, such as stainless steel rectangular tubes, aluminum alloy rectangular tubes, or plastic rectangular tubes, etc..

Optionally, the materials of the first frame <NUM> and the second frame <NUM> are not limited, and the first frame and the second frame may be made of steel, an aluminum alloy, or plastics.

Some embodiments of the present application further provide an electrode plate manufacturing apparatus, comprising a coating device and the drying device <NUM> as described above, the coating device being configured for coating a slurry on a surface of an electrode plate. In a movement direction of the electrode plate, the drying device <NUM> is disposed downstream of the coating device for drying the slurry on the electrode plate.

The coating device is an apparatus that can evenly coat the slurry (an active material) on a current collector, i.e., the electrode plate. The drying device <NUM> is an apparatus that can quickly dry the slurry on the electrode plate.

The drying device <NUM> described above can increase the drying efficiency of the electrode plate while ensuring the drying quality of the electrode plate, thereby increasing the production efficiency of a battery.

Some embodiments of the present application further provide a drying device <NUM>, see <FIG>. The drying device <NUM> comprises a first oven section <NUM>, a second oven section <NUM> and a third oven section <NUM>. The first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are arranged sequentially in a movement direction of an electrode plate. The first oven section <NUM>, the second oven section <NUM> and the third oven section <NUM> are supplied with air from the same air source. The second oven section <NUM> has a larger air outlet area than the first oven section <NUM>, and the first oven section <NUM> has a larger air outlet area than the third oven section <NUM>, such that the air speed of the first oven section <NUM> is greater than that of the second oven section <NUM>, and the air speed of the third oven section <NUM> is greater than that of the first oven section <NUM>. In this embodiment, the first oven section <NUM> has an air speed of less than <NUM>/s, the second oven section <NUM> has an air speed of less than <NUM>/s, and the third oven section <NUM> has an air speed of <NUM>-<NUM>/s.

In the movement direction of the electrode plate, the first oven section <NUM> is provided with at least <NUM> first tuyeres <NUM> per <NUM>, such that the air outlet area of the first oven section <NUM> is not less than <NUM>,<NUM><NUM>/<NUM>; the second oven section <NUM> is provided with at least <NUM> second tuyeres <NUM> per <NUM>, such that the air outlet area of the second oven section <NUM> is not less than <NUM>,<NUM><NUM>/<NUM>; and the third oven section <NUM> is provided with at least <NUM> third tuyeres <NUM> per <NUM>, such that the air outlet area of the third oven section <NUM> is not less than <NUM>,<NUM><NUM>/<NUM>. In each oven section, the center-to-center distance between two adjacent tuyeres is not greater than <NUM> (that is, the minimum distance between adjacent first tuyeres is <NUM>, and the minimum distance between adjacent second tuyeres <NUM>, and the minimum distance between adjacent third tuyeres is <NUM>). The volume of air of the first oven section <NUM> accounts for <NUM>-<NUM>% of the total volume of air of the drying device <NUM>, the volume of air of the second oven section <NUM> accounts for <NUM>-<NUM>% of the total volume of air of the drying device <NUM>, and the volume of air of the third oven section <NUM> accounts for <NUM>-<NUM>% of the total volume of air of the drying device <NUM>.

In the first oven section <NUM> and the second oven section <NUM>, the first tuyeres <NUM> and the second tuyeres <NUM> each comprises an air outlet face structure <NUM>, and the air outlet surface structure <NUM> comprises a boosting part <NUM> and an air outlet part <NUM>. The boosting part comprises a first frame <NUM> of steel and a plurality of first connecting portions <NUM>, the first connecting portions <NUM> being stainless steel rectangular tubes. The plurality of first connecting portions <NUM> are arranged at intervals in the first frame <NUM> to form a plurality of first slits <NUM>. The air outlet part <NUM> comprises a second frame <NUM> of steel and a plurality of second connecting portions <NUM>, the second connecting portions <NUM> being stainless steel rectangular tubes. The plurality of second connecting portions <NUM> are arranged at intervals in the second frame <NUM> to form a plurality of second slits <NUM>. The air outlet part <NUM> is placed in the first frame <NUM> such that the first connecting portions <NUM> and the second connecting portions <NUM> are spaced apart from each other, and the first slits <NUM> are staggered with the second slits <NUM>. The airflow in the oven passes through the first slits <NUM> of the boosting part <NUM>, then passes through the second slits <NUM> of the air outlet part <NUM>, and finally is blown to the electrode plate. In the first tuyeres <NUM>, the air outlet area of the air outlet part <NUM> accounts for <NUM>-<NUM>% of the total area of the air outlet part <NUM>, and the widths of the first slits <NUM> and the second slits <NUM> are between <NUM>-<NUM>, the number of the first slits <NUM> and the number of the second slits <NUM> are between <NUM>-<NUM> respectively, and the total air outlet area of the air outlet part <NUM> is not less than <NUM>,<NUM><NUM>. In the second tuyeres <NUM>, the air outlet area of the air outlet part <NUM> accounts for <NUM>-<NUM>% of the total area of the air outlet part <NUM>, the widths of the first slits <NUM> and the second slits <NUM> are between <NUM>-<NUM>, the numbers of the first slit <NUM> and the number of the second slits <NUM> are between <NUM>-<NUM> respectively, the total air outlet area of the air outlet part <NUM> is not less than <NUM>,<NUM><NUM>, and the gap between the boosting part <NUM> and the air outlet part <NUM> is between <NUM>-<NUM>.

For ease of understanding, this embodiment provides Table <NUM> to clearly illustrate the data of various factors in the oven device.

In Table <NUM>, volume of air = air speed * total air outlet area of a single oven section * number of ovens sections/<NUM> * <NUM>. The distribution ratio of the volume of air may range from: <NUM>-<NUM>% for the first oven section <NUM>, <NUM>-<NUM>% for the second oven section <NUM> and <NUM>-<NUM>% for the third oven section <NUM>. The number of the tuyeres of each oven section is <NUM>, and the total volume of air of the oven device is <NUM><NUM>/h.

Claim 1:
A drying device (<NUM>) for drying a material, comprising:
a first oven section (<NUM>);
a second oven section (<NUM>); and
a third oven section (<NUM>), the drying device is configured so that the material move and passes through the first oven section (<NUM>), the second oven section (<NUM>) and the third oven section (<NUM>) sequentially,
wherein the second oven section (<NUM>) has a larger air outlet area than the first oven section (<NUM>), and the first oven section (<NUM>) has a larger air outlet area than the third oven section (<NUM>);
the first oven section (<NUM>) has a plurality of first tuyeres (<NUM>), the second oven section (<NUM>) has a plurality of second tuyeres (<NUM>), and the third oven section (<NUM>) has a plurality of third tuyeres (<NUM>), both of the first tuyeres (<NUM>) and the second tuyeres (<NUM>) have a larger air outlet area than the third tuyeres (<NUM>);
the first tuyeres (<NUM>) and the second tuyeres (<NUM>) each comprise an air outlet face structure (<NUM>), and the air outlet face structure (<NUM>) comprises a boosting part (<NUM>) and an air outlet part (<NUM>) which are superposed in an air outlet direction with a gap therebetween, the boosting part (<NUM>) is formed with a plurality of first slits (<NUM>) at intervals, and the air outlet part (<NUM>) is formed with a plurality of second slits (<NUM>), the first slits (<NUM>) being staggered with the second slits (<NUM>);
the boosting part (<NUM>) comprises a first frame (<NUM>) and a plurality of first connecting portions (<NUM>) arranged in the first frame (<NUM>), each of the first connecting portions (<NUM>) is connected to the first frame (<NUM>) at two ends, and the first slits (<NUM>) are formed between two adjacent ones of the first connecting portions (<NUM>).