A fluidized bed spray coating device

Abstract

The present invention discloses a fluidized bed spray coating device, which includes: a fixed base, a mixing device is arranged on the fixed base, and the mixing device is used to mix the liquid or slurry used for coating the crystal nucleus uniformly; a spray coating device, the spray coating device has a spray coating chamber, and is arranged above the fixed base and connected to the mixing device, and is used to send the liquid or slurry mixed uniformly by the mixing device into the spray coating chamber, and coat and dry the crystal nucleus sent into the spray coating chamber; a well-shaped air inlet screening device, the well-shaped air inlet screening device is connected to the spray coating device, and is used to separate the spray coating chamber into a fluidized bed coating area and a solid material collection area, and suspend the crystal nucleus sent into the spray coating chamber in the fluidized bed coating area to form a fluidized bed. The present invention can obtain solid gradient positive electrode material coated particles with uniform particle size and uniform coating layer, so as to meet the requirements of the battery positive electrode material for the spherical shape, particle size distribution and tap density of the finished product.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy and new energy material preparation, and in particular to a fluidized bed spray coating device. Background Art

[0002] Powder metallurgy products often go far beyond the scope of materials and metallurgy, and are often cross-disciplinary technologies. Spray dryer is a type of continuous atmospheric pressure dryer. Spray drying is a drying process in which the raw material liquid is sprayed into a mist by special equipment, and the powder-shaped product is obtained by direct contact between hot air or other gases and droplets. Spray drying has the advantage of fast speed. It only takes a few seconds to complete the drying. It is suitable for drying heat-sensitive materials and is mainly used for drying some heat-sensitive liquids, suspensions and viscous liquids, such as drugs and materials. Since the drying process is completed in an instant, the resulting finished particles can basically maintain the approximate spherical shape of the droplets. The product has good dispersibility, fluidity and solubility, and the production process is simplified and the operation and control are convenient. However, the products produced by traditional spray drying equipment are often in the form of powder, granules, hollow balls or agglomerates. The products are easy to agglomerate, and it is impossible to accurately control the shape, size distribution, residual moisture content, bulk density, etc. of the finished particles. As a result, various problems such as uneven coating and broken hollow balls are easily generated during the material coating process, and the requirements of battery positive electrode materials for the spherical shape, particle size distribution and tap density of the finished products cannot be met.

[0003] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a fluidized bed spray coating device to solve the problem that traditional spray drying equipment is prone to uneven coating and broken hollow balls during the material coating process, so as to meet the requirements of battery positive electrode materials for finished product sphericity, particle size distribution and tap density.

[0005] The technical solution of the present invention is as follows:

[0006] A fluidized bed spray coating device, the device comprising:

[0007] A fixed base, wherein a mixing device is provided on the fixed base, and the mixing device is used to evenly mix the liquid or slurry for coating the crystal nuclei;

[0008] A spray coating device, wherein the spray coating device has a spray coating chamber, is disposed above the fixed base, and is connected to the mixing device, and is used to deliver the liquid or slurry evenly mixed by the mixing device into the spray coating chamber, and to coat and dry the crystal nuclei delivered into the spray coating chamber; and

[0009] A well-shaped air inlet screening device is connected to the spray coating device, and is used to separate the spray coating chamber into a fluidized bed coating area and a solid material collection area, and suspend the crystal nuclei delivered into the spray coating chamber in the fluidized bed coating area to form a fluidized bed.

[0010] According to a further configuration of the present invention, the apparatus further comprises a solid material collecting device, wherein the solid material collecting device is arranged at the bottom of the spray coating device and is used for collecting the crystal nuclei coated and dried by the spray coating device.

[0011] According to a further configuration of the present invention, the spray coating device comprises:

[0012] A plurality of fixing columns, wherein the fixing columns are arranged on the fixing base;

[0013] A spray coating tower, wherein the spray coating tower is arranged on the fixed column; wherein the spray coating tower is arranged hollow to form the spray coating chamber; exhaust holes are arranged at the top and the bottom of the spray coating tower, and the exhaust holes extend into the spray coating chamber;

[0014] An ultrafine atomizer, the ultrafine atomizer is arranged at the top of the spray coating tower; the ultrafine atomizer is provided with a liquid inlet and a first liquid outlet pipe, the first liquid outlet pipe is connected to the liquid inlet, the liquid inlet is arranged perpendicular to the spray coating tower and extends to the fluidized bed coating area;

[0015] A heat pump system component, wherein a first liquid inlet pipe is provided on the heat pump system component, wherein both ends of the first liquid inlet pipe are respectively connected to the mixing device and the heat pump system component, and both ends of the first liquid outlet pipe are respectively connected to the liquid inlet and the heat pump system component, for delivering the liquid or slurry evenly mixed by the mixing device into the liquid inlet.

[0016] In a further embodiment of the present invention, the spray coating tower comprises:

[0017] a housing, the heat pump system components being arranged on the housing;

[0018] An inner box and an outer box, the outer box is spaced apart from the inner box and forms a cavity with the inner box, and the shell is arranged on the outer box;

[0019] a heating wire, the heating wire being disposed in the cavity and electrically connected to the heat pump system component; and

[0020] The heat insulation layer is made of a heat insulation material, and the heat insulation material is filled between the outer box and the heating wire.

[0021] According to a further configuration of the present invention, the well-shaped air inlet screening device comprises:

[0022] A well-shaped air inlet screening component is arranged in the spray coating chamber and divides the spray coating chamber into a fluidized bed coating area and a solid material collection area;

[0023] A driving assembly, the driving assembly being arranged below the well-shaped air inlet screening assembly and being used for driving the well-shaped air inlet screening assembly to rise and fall in the spray coating chamber;

[0024] A blower is arranged on the fixed base and connected to the well-shaped air inlet screening assembly and is located below the spray coating device, and is used to provide an air source for the well-shaped air inlet screening assembly to suspend the crystal nuclei to form a fluidized bed in the spray coating chamber.

[0025] According to a further configuration of the present invention, the well-shaped air inlet screening assembly comprises:

[0026] An air inlet sieve plate, the air inlet sieve plate is connected to the blower through an air duct;

[0027] A grid-type air inlet passage, the grid-type air inlet passage is in a grid shape and is arranged on the air inlet screen plate;

[0028] An air inlet, the air inlet being arranged at the intersection of the grid-type air inlet channel;

[0029] A filter screen connected to the air inlet screen plate and located at the bottom of the grid-type air inlet channel; and

[0030] A cleaning brush is arranged on the side of the air inlet screen plate and abuts against the inner wall of the spray coating chamber.

[0031] According to a further configuration of the present invention, the well-shaped air inlet screening assembly also includes a hood, which is arranged on the air inlet and is detachably connected to the air inlet; a plurality of air inlet holes are arranged on the hood, and the air inlet direction of the air inlet holes faces downward and forms an angle with the horizontal plane; wherein the size of the angle is 30-50°.

[0032] According to a further configuration of the present invention, crystal nucleus feed inlets are symmetrically arranged on the side walls of the fluidized bed coating zone, and the crystal nucleus feed inlets penetrate the shell, the outer box body and the inner box body.

[0033] According to a further configuration of the present invention, the driving assembly includes a telescopic rod and a driving motor arranged on the telescopic rod, and the telescopic rod is arranged at the bottom end of the interior of the spray coating tower and is connected to the grid-type air inlet channel.

[0034] According to a further configuration of the present invention, a first valve is provided between the solid material collecting device and the solid material collecting area, and a second valve is connected between the solid material collecting device and the outside.

[0035] The present invention provides a fluidized bed spray coating device, which includes: a fixed base, on which a mixing device is provided, and the mixing device is used to evenly mix the liquid or slurry for coating the crystal nucleus; a spray coating device, which has a spray coating chamber and is arranged above the fixed base and connected to the mixing device, and is used to send the liquid or slurry evenly mixed by the mixing device into the spray coating chamber, and to coat and dry the crystal nuclei sent into the spray coating chamber; and a well-shaped air inlet screening device, which is connected to the spray coating device, and is used to separate the spray coating chamber into a fluidized bed coating area and a solid material collection area, and suspend the crystal nuclei sent into the spray coating chamber in the fluidized bed coating area to form a fluidized bed. The present invention can obtain solid gradient positive electrode material coated particles with uniform particle size and uniform coating layer, so as to meet the requirements of battery positive electrode materials for finished product sphericity, particle size distribution and tap density. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary personnel in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0037] Figure 1 It is a schematic diagram of the overall structure of the fluidized bed spray coating equipment in the present invention.

[0038] Figure 2 It is a partial structural schematic diagram of the well-shaped air inlet screening assembly in the present invention.

[0039] Figure 3 It is a partial structural schematic diagram of the well-shaped air inlet screening assembly in the present invention from another angle.

[0040] Figure 4 It is a top view of the hood of the present invention.

[0041] Figure 5 It is a side view of the hood of the present invention.

[0042] Figure 6 It is a side view of the hood of the present invention from another angle.

[0043] The marks in the attached drawings are: 1, fixed base; 2, mixing device; 3, spray coating device; 31, fixed column; 32, spray coating tower; 321, shell; 322, inner box; 323, outer box; 324, electric heating wire; 325, insulation layer; 326, crystal nucleus feed port; 327, exhaust hole; 33, ultra-fine atomizer; 331, first liquid outlet pipe; 34, heat pump system component; 341, first liquid inlet pipe; 4, well-shaped air inlet screening Device; 41. Well-shaped air inlet screening component; 411. Air inlet screen plate; 412. Grid-type air inlet channel; 413. Air inlet; 414. Filter; 415. Cleaning brush; 416. Wind hood; 4161. Wind hood body; 4162. Air inlet hole; 42. Drive component; 421. Telescopic rod; 422. Drive motor; 43. Blower; 431. Air duct; 5. Solid material collection device; 51. First valve; 52. Second valve. DETAILED DESCRIPTION

[0044] The present invention provides a fluidized bed spray coating device, which can be used for the preparation and regeneration of lithium battery positive electrode materials. The present invention is based on fluidized bed technology and spray drying principles, combines fluidized bed technology with spray drying technology, realizes uniform coating and rapid drying of positive electrode materials, and can realize low-cost preparation of gradient positive electrode materials. In order to make the purpose, technical scheme and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] In the embodiments and patent claims, unless otherwise specified, "a", "an" and "the" may refer to a single or a plurality of items.

[0046] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] In order to better understand the present invention, the positive electrode material is first explained: the positive electrode material is one of the key materials that determine the performance of lithium-ion batteries, and is also the main source of lithium ions in commercial lithium-ion batteries. Its performance and price have a great impact on lithium-ion batteries. At present, the positive electrode materials that have been successfully developed and applied mainly include lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, ternary materials nickel cobalt manganese oxide (NCM) and nickel cobalt aluminum oxide (NCA). Among them, the ternary positive electrode material can be divided into different grades such as 111, 523, 622, 811 according to the molar fraction ratio of each metal. With the increase of nickel content, the specific capacity of the ternary positive electrode material gradually increases, but the cycle performance and safety performance also deteriorate accordingly. Surface coating can effectively inhibit the side reaction of high nickel materials and electrolytes and improve the cycle stability of materials. If the coating layer is too thin, the material performance is not significantly improved; if the coating layer is too thick, the material specific capacity loss is large, and after multiple cycles, the film falls off. If the positive electrode material with the same structure is coated, the coating thickness is large and completely coated on the outside of the particle to form a core-shell structure, it is possible to suppress the above defects. The core-shell structure ternary positive electrode material is usually composed of a core with high specific capacity and a shell with high stability. Both the core and the shell are electrochemically active, and have the advantages of high specific capacity and good cycle stability.

[0048] The present invention couples the seed fluidized bed technology with the spray drying principle, and can achieve mutual coating between different materials by controlling the different component ratios of the seed crystals and the spray drying liquid. For example, the seed crystal uses a ternary positive electrode material of brand 811, and the spray drying liquid uses a nickel, cobalt, and manganese ratio of 111, so as to achieve the preparation of a 811-111 gradient positive electrode material.

[0049] Please also see Figures 1 to 6 The present invention provides a preferred embodiment of a fluidized bed spray coating device.

[0050] like Figure 1As shown in the figure, a fluidized bed spray coating device provided by the present invention includes a fixed base 1, a mixing device 2, a spray coating device 3, a well-shaped air inlet screening device 4, and a solid material collection device 5. Specifically, the mixing device 2 is installed on the fixed base 1 and is located on one side of the spray coating device 3. The mixing device 2 can be selected from ultrasonic mixing or forced stirring mixing. Through the mixing device 2, the liquid or slurry for coating the crystal nuclei can be mixed evenly. The spray coating device 3 is arranged above the fixed base 1 and is connected to the mixing device 2. The spray coating device 3 has a spray coating chamber. The spray coating device 3 can send the liquid or slurry evenly mixed by the mixing device 2 into the spray coating chamber, and coat and dry the crystal nuclei sent into the spray coating chamber. The well-shaped air inlet screening device 4 is connected to the spray coating device 3 and is partially located in the spray coating chamber. It can divide the spray coating chamber into a fluidized bed coating area and a solid material collection area, and suspend the crystal nuclei sent into the spray coating chamber in the fluidized bed coating area to form a fluidized bed. The solid material collection device 5 is arranged at the bottom of the spray coating device 3. In some embodiments, the solid material collection device 5 can be a material collection tank for collecting the crystal nuclei coated and dried by the spray coating device 3.

[0051] By combining the fluidized bed technology and the spray drying technology, that is, through the well-shaped air inlet screening device 4, the crystal nuclei form a uniform fluidized bed layer, and then through the coating and rapid drying of the spray coating device 3, the present invention can accurately control the shape, size distribution, residual moisture content, bulk density, etc. of the finished positive electrode material particles, so as to obtain solid gradient positive electrode material coated particles with uniform particle size and uniform coating layer, thereby meeting the requirements of the battery positive electrode material for the sphericity, particle size distribution, and tap density of the finished product, and further realizing the preparation of the gradient positive electrode material. It should be noted that the fluidized bed has a selective screening effect on particles of different particle sizes: that is, the suspended material particles exceeding the critical size of the fluidized bed will settle downward, while when the particle size is too small, they will be blown away from the fluidized bed layer by the air flow, thereby realizing the particle size control of the product.

[0052] When this equipment is used for the preparation of the positive electrode material of a lithium-ion battery, Q is used as the fluidized bed seed crystal, where. The composition of Q can be any one of lithium cobaltate, lithium manganate, LiNi 1-x-y CoxMnyO2(0 < x + y ≤ 0.66), LiNi 1-a-b CoaAlbO2(0 < a + b ≤ 0.2) and other lithium-ion positive electrode materials, or it can be Ni 1-x-y CoxMny(OH)2(0 < x + y ≤ 0.66), Ni 1-a-bAny one of the composite precursor cathode materials such as CoaMnb(OH)2(0 < a + b ≤ 0.2). The liquid or slurry used in the spray coating device 3 can be a Ni, Co, Mn or Ni, Co, Al salt solution mixed according to the molar ratio of the target coating layer components, or a liquid or slurry composed of one or more of ternary composite precursors, soluble metal lithium compounds, and rare earth compounds. When this equipment is used for the regeneration of the cathode material of waste lithium-ion batteries, first, the cathode material obtained after disassembling the waste battery is pre-leached with a salt solution, organic acid or inorganic acid to remove the solid electrolyte interface (SEI) film or surface contamination layer that has thickened on the surface, and then the above-mentioned pre-leached cathode material particles are used as fluidized bed seeds. The leaching solution that has dissolved the SEI film or surface layer on the surface of the waste cathode material after the above-mentioned pre-leaching is purified and formulated according to the molar ratio of the target coating layer components, and the formulated leaching solution is used as the liquid or slurry added to the spray coating device 3. Please continue to refer to Figure 1 , in a further implementation manner of an embodiment, the spray coating device 3 includes a plurality of fixed columns 31, a spray coating tower 32, an ultra-fine atomizer 33, and a heat pump system assembly 34. Specifically, the fixed columns 31 are arranged on the fixed base 1. In some implementation manners, there are two fixed columns 31, which are fixedly arranged at intervals on the fixed base 1, and the spray coating tower 32 is arranged on the fixed columns 31 so that there is a certain distance between the spray coating tower 32 and the fixed base 1.

[0053] Please continue to refer to Figure 1, further, the spray coating tower 32 is hollow to form the spray coating chamber, the ultrafine atomizer 33 is arranged at the top of the spray coating tower 32, wherein the ultrafine atomizer 33 is provided with a liquid inlet (not shown in the figure) and a first liquid outlet pipe 331, the first liquid outlet pipe 331 is connected to the liquid inlet, the liquid inlet is arranged perpendicular to the spray coating tower 32 and extends to the fluidized bed coating area, the heat pump system component 34 is provided with a first liquid inlet pipe 341, the two ends of the first liquid inlet pipe 341 are respectively connected to the mixing device 2 and the heat pump system component 34, and the two ends of the first liquid outlet pipe 331 are respectively connected to the liquid inlet and the heat pump system component 34. More specifically, the heat pump system component 34 includes components such as a temperature controller and a heat pump, the first liquid outlet pipe 331 connects the heat pump and the liquid inlet, and the first liquid inlet pipe 341 connects the heat pump and the mixing device 2. The present invention can deliver the uniformly mixed liquid or slurry through the mixing device 2 to the liquid inlet through the heat pump system component 34, and then the uniformly mixed liquid or slurry is atomized by the ultrafine atomizer 33 and enters the spray coating chamber (drying chamber) to wrap and dry the crystal nuclei forming the fluidized bed in the spray coating chamber. Furthermore, the top and bottom of the spray coating tower 32 are both provided with exhaust holes 327, and the exhaust holes 327 extend into the spray coating chamber to prevent the air pressure in the spray coating chamber from being too high.

[0054] Please continue reading Figure 1 In a further implementation of an embodiment, the spray coating tower 32 includes a shell 321, an inner box 322, an outer box 323, a heating wire 324 and a heat insulation layer 325. Specifically, the heat pump system component 34 is arranged on the shell 321, and the outer box 323 and the inner box 322 form a double-layer structure, that is, the outer box 323 and the inner box 322 are spaced apart and form a cavity with the inner box 322, the shell 321 is arranged on the outer box 323, the heating wire 324 is arranged in the cavity, and is electrically connected to the temperature controller of the heat pump system component 34. Furthermore, the thermal insulation layer 325 is made of a thermal insulation material, and the thermal insulation material is filled between the outer box body 323 and the heating wire 324, and has a heat preservation effect. Therefore, the heat pump system component 34 can adjust the temperature of the heating wire 324, so that the ultra-fine atomizer 33 can achieve different temperature setting requirements when spraying and coating.

[0055] See also Figure 1 , Figure 2 and Figure 3In a further implementation of an embodiment, the well-shaped air inlet screening device 4 includes a well-shaped air inlet screening component 41, a driving component 42 and a blower 43. Specifically, the well-shaped air inlet screening component 41 is arranged in the spray coating chamber and divides the spray coating chamber into a fluidized bed coating area and a solid material collection area. The driving component 42 is vertically arranged below the well-shaped air inlet screening component 41, and is used to drive the well-shaped air inlet screening component 41 to rise and fall in the spray coating chamber. The blower 43 is arranged on the fixed base 1 and connected to the well-shaped air inlet screening component 41, and is located below the spray coating device 3, and is used to provide an air source for the well-shaped air inlet screening component 41 to suspend the crystal nuclei into a fluidized bed in the spray coating chamber. Furthermore, a crystal nucleus feed port 326 is symmetrically arranged on the side wall of the fluidized bed coating area, and the crystal nucleus feed port 326 passes through the shell 321, the outer box 323 and the inner box 322.

[0056] Specifically, the well-shaped air inlet screening component 41 is connected to the blower 43 through an air duct 431, wherein the well-shaped air inlet screening component 41 is connected to the blower 43 by bottom air inlet, and in addition, the crystal nucleus feed port 326 has a separate air source, and driven by the air source, the crystal nucleus can enter the spray coating chamber through the crystal nucleus feed port 326. In some embodiments, a pair of crystal nucleus feed ports 326 are symmetrically arranged on the side wall of the fluidized bed coating zone, and it can be understood that two pairs of crystal nucleus feed ports 326 or multiple pairs of crystal nucleus feed ports 326 can also be symmetrically arranged on the side wall of the fluidized bed coating zone according to actual needs. The present invention can deliver the crystal nuclei from the crystal nucleus feed port 326 into the spray coating chamber through the blast airflow (separate air source), and at the same time, under the action of the blower 43, the air inlet at the bottom of the well-shaped air inlet screening component 41 will enter the crystal nuclei in the spray coating chamber to form a fluidized bed, and then after coating and drying by the ultra-fine atomizer 33, solid gradient positive electrode material coated particles with uniform particle size and uniform coating layer can be obtained. It should be noted that, considering the rapid spray drying reaction, the thickness of the reaction zone where the liquid flow (feed liquid) is sprayed into the fluidized bed layer from the liquid inlet is limited, and the well-shaped air inlet screening component 41 is designed to be liftable. By adjusting the lifting speed and the lifting position height of the well-shaped air inlet screening component 41, and controlling the contact time and contact area between crystal nuclei of different sizes and types and the feed liquid, the thickness and uniformity of the coating layer on the surface of the crystal nuclei can be adjusted.

[0057] Please also see Figures 1 to 6In a further implementation of an embodiment, the well-shaped air inlet screening assembly 41 includes an air inlet screen plate 411, a grid-type air inlet channel 412, an air inlet 413, a filter 414, and a cleaning brush 415. Specifically, the air inlet screen plate 411 is connected to the blower 43 through an air duct 431, the grid-type air inlet channel 412 is in a grid shape and is arranged on the air inlet screen plate 411, the air inlet 413 is arranged at the intersection of the grid-type air inlet channel 412, the filter 414 is connected to the air inlet screen plate 411 and is located at the bottom of the grid-type air inlet channel 412, the cleaning brush 415 is arranged on the side of the air inlet screen plate 411 and abuts against the inner wall of the spray coating chamber, wherein the cleaning brush 415 is detachably connected to the air inlet screen plate 411. Furthermore, the well-shaped air inlet screening assembly 41 also includes a hood 416, and the hood 416 is arranged on the air inlet 413. The hood 416 includes a hood body 4161 and a plurality of air inlet holes 4162 arranged on the hood body 4161. The air inlet direction of the air inlet holes 4162 is downward and forms an angle α with the horizontal plane. The angle α is 30-50°. In one implementation, the angle α can be set to 45°. More specifically, the hood 416 is detachably connected to the air inlet 413. For example, the hood 416 can be sleeved on the air inlet 413, or the hood 416 can be threadedly connected to the air inlet 413.

[0058] When the blower 43 is started, the blast airflow enters the grid-type air inlet channel 412 from the air inlet sieve plate 411, and then flows out from the air inlet hole 4162 of the hood 416 through the air inlet 413, wherein the air inlet hole 4162 is an air inlet hole 4162 with a uniform inner diameter, and the position of the air inlet hole 4162 on the hood 416, the size of the air inlet hole 4162, the opening angle, and the size of the air inlet airflow can be adjusted to ensure that the crystal nuclei sprayed from the crystal nucleus feed port 326 float in the spray coating chamber and form a fluidized bed, so that crystal nuclei of different sizes and densities can form a fluidized bed in this device. When the crystal nuclei forming the fluidized bed are coated and dried by the ultrafine atomizer 33, and when the density of the coated and grown crystal nuclei (positive electrode material) exceeds the average density of the set fluidized bed, the crystal nuclei will settle downward and pass through the filter 414 into the solid material collection device 5 below. The present invention can make the coating liquid and the crystal nucleus mix evenly through this countercurrent structure design, so as to achieve the particle size uniformity control in the coating and drying process of the positive electrode material. It should be noted that in order to ensure that the crystal nucleus is in a fluidized bed state, the number, aperture and opening angle of the air inlet holes 4162 of the hood 416 can be selected according to the size and physical property parameters of the crystal nucleus used in the actual positive electrode material preparation or regeneration process.

[0059] See also Figure 1In a further implementation of an embodiment, the driving assembly 42 includes a telescopic rod 421 and a driving motor 422 arranged on the telescopic rod 421, and the telescopic rod 421 is arranged at the bottom end of the spray coating tower 32 and connected to the grid-type air inlet channel 412. Specifically, the telescopic rod 421 is fixed to the bottom end of the spray coating tower 32 and connected to the grid-type air inlet channel 412, and plays a role in supporting the operation of the well-shaped air inlet sieve plate assembly 411, and can realize the lifting and lowering control of the well-shaped air inlet sieve plate assembly 411 to form an optimal fluidized bed spray coating area. Specifically, the telescopic rod 421 is fixed in the middle position of the grid-type air inlet channel 412. In addition, since a cleaning brush 415 is installed at the edge of the air inlet sieve plate 411, the driving assembly 42 can simultaneously drive the cleaning brush 415 to move up and down during the process of driving the air inlet sieve plate 411 to lift and lower, so that the particles adhering to the inner wall of the spray coating chamber (drying chamber) can be cleaned during the process of lifting and lowering the air inlet sieve plate 411. In one implementation, the air duct 431 of the blower 43 may be connected to the telescopic rod 421 , and the blast airflow is delivered to the grid-type air inlet channel 412 through the telescopic rod 421 .

[0060] Please continue reading Figure 1 In a further implementation of an embodiment, a first valve 51 is provided between the solid material collecting device 5 and the solid material collecting area, and a second valve 52 is connected between the solid material collecting device 5 and the outside. Specifically, when spray drying is performed, the second valve 52 connected to the solid material collecting device 5 and the outside is closed, and the first valve 51 connected to the solid material collecting area is opened. When discharging (when the density of the coated and grown positive electrode material exceeds the set average density of the fluidized bed layer), the second valve 52 connected to the solid material collecting device 5 and the outside is closed, and the first valve 51 connected to the solid material collecting area is opened, so that the pressure in the spray coating area can be ensured to be stable, and continuous discharge of positive electrode material products can be achieved.

[0061] In specific implementation, that is, when the spray coating equipment is working, it is first started through the menu control panel, the mixing device 2 mixes the coating liquid or slurry evenly, and the mixed liquid or slurry is sent to the liquid inlet of the ultrafine atomizer 33 through the heat pump, and is atomized into the drying chamber through the ultrafine atomizer 33. In addition, the crystal nucleus feed port 326 on the side wall sends the crystal nucleus into the spray coating chamber through the blast air flow. At the same time, the blower 43 connected to the grid-type air inlet channel 412 at the bottom is started to blow a uniform air flow upward into the grid-type air inlet channel 412 at the bottom. The air flow passes through the wind hood 416 to form a fluidized bed for the crystal nucleus to be suspended in the spray coating tower 32. The telescopic rod 421 (motor-driven telescopic rod 421) is started and moved upward to form an optimal fluidized bed spray coating area, and the crystal nucleus is coated and dried. The positive electrode material particles that have grown up after coating will settle downward when their size exceeds the critical size corresponding to the average density of the fluidized bed layer, and enter the solid material collection device 5 through the filter screen 414 on the well-shaped air inlet screen plate 411, thereby achieving the purpose of uniform coating and rapid drying of the positive electrode material.

[0062] In summary, the present invention provides a fluidized bed spray coating device, which includes: a fixed base, on which a mixing device is provided, and the mixing device is used to evenly mix the liquid or slurry for coating the crystal nuclei; a spray coating device, which has a spray coating chamber, and is arranged above the fixed base and connected to the mixing device, and is used to send the liquid or slurry evenly mixed by the mixing device into the spray coating chamber, and to coat and dry the crystal nuclei sent into the spray coating chamber; and a well-shaped air inlet screening device, which is connected to the spray coating device, and is used to separate the spray coating chamber into a fluidized bed coating area and a solid material collection area, and suspend the crystal nuclei sent into the spray coating chamber in the fluidized bed coating area to form a fluidized bed. The present invention has the advantages of low cost, precise control, and can realize automatic control, saving manual operation. In addition, the present invention can make the coating liquid and the crystal nucleus mix evenly through the countercurrent structure design, and combined with the seed fluidized bed technology, solid, gradient spherical particles with uniform coating layer can be generated. Therefore, the use of this equipment can realize the accurate control of the shape, size distribution, residual moisture content, bulk density, etc. of the finished positive electrode material particles, and can obtain solid gradient positive electrode material coated particles with uniform particle size and uniform coating layer, so as to meet the requirements of the battery positive electrode material for the finished product spherical shape, particle size distribution and tap density, thereby realizing the preparation of gradient positive electrode material.

[0063] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A fluidized bed spray coating device, characterized in that: include: A fixed base, wherein a mixing device is provided on the fixed base, and the mixing device is used to evenly mix the liquid or slurry for coating the crystal nuclei; A spray coating device, wherein the spray coating device has a spray coating chamber, is disposed above the fixed base, and is connected to the mixing device, and is used to deliver the liquid or slurry evenly mixed by the mixing device into the spray coating chamber, and to coat and dry the crystal nuclei delivered into the spray coating chamber; as well as A well-shaped air inlet screening device, which is connected to the spray coating device and is used to separate the spray coating chamber into a fluidized bed coating area and a solid material collection area, and suspend the crystal nuclei fed into the spray coating chamber in the fluidized bed coating area to form a fluidized bed; The spray coating device comprises: A plurality of fixing columns, wherein the fixing columns are arranged on the fixing base; A spray coating tower, wherein the spray coating tower is arranged on the fixed column, and there is a distance between the spray coating tower and the fixed base; wherein the spray coating tower is hollow to form the spray coating chamber; An ultrafine atomizer, wherein the ultrafine atomizer is arranged at the top of the spray coating tower; The well-shaped air inlet screening device comprises: A well-shaped air inlet screening component is arranged in the spray coating chamber and divides the spray coating chamber into a fluidized bed coating area and a solid material collection area; A driving assembly, the driving assembly being arranged below the well-shaped air inlet screening assembly and being used for driving the well-shaped air inlet screening assembly to rise and fall in the spray coating chamber; A blower, the blower is arranged on the fixed base, connected to the well-shaped air inlet screening assembly, and located below the spray coating device, and is used to provide an air source for the well-shaped air inlet screening assembly to suspend the crystal nucleus forming fluidized bed in the spray coating chamber; It also includes a solid material collecting device, which is arranged at the bottom of the spray coating device and is used to collect the crystal nuclei coated and dried by the spray coating device.

2. The fluidized bed spray coating equipment according to claim 1, characterized in that: The top and bottom of the spray coating tower are both provided with exhaust holes, and the exhaust holes extend into the spray coating chamber; The ultrafine atomizer is provided with a liquid inlet and a first liquid outlet pipe, the first liquid outlet pipe is connected to the liquid inlet, and the liquid inlet is arranged perpendicular to the spray coating tower and extends to the fluidized bed coating area; The spray coating device also includes: A heat pump system component, wherein a first liquid inlet pipe is provided on the heat pump system component, wherein both ends of the first liquid inlet pipe are respectively connected to the mixing device and the heat pump system component, and both ends of the first liquid outlet pipe are respectively connected to the liquid inlet and the heat pump system component, for delivering the liquid or slurry evenly mixed by the mixing device into the liquid inlet.

3. The fluidized bed spray coating equipment according to claim 2, characterized in that: The spray coating tower comprises: a housing, the heat pump system components being arranged on the housing; An inner box and an outer box, wherein the outer box is spaced apart from the inner box and forms a cavity with the inner box; the shell is arranged on the outer box; a heating wire, the heating wire being disposed in the cavity and electrically connected to the heat pump system component; and The heat insulation layer is made of a heat insulation material, and the heat insulation material is filled between the outer box and the heating wire.

4. The fluidized bed spray coating equipment according to claim 1, characterized in that: The well-shaped air inlet screening assembly comprises: Air inlet screen; A grid-type air inlet passage, the grid-type air inlet passage is in a grid shape and is arranged on the air inlet screen plate; the grid-type air inlet passage is connected to the blower through an air duct; An air inlet, the air inlet being arranged at the intersection of the grid-type air inlet channel; A filter screen connected to the air inlet screen plate and located at the bottom of the grid-type air inlet channel; and A cleaning brush is arranged on the side of the air inlet screen plate and abuts against the inner wall of the spray coating chamber.

5. The fluidized bed spray coating equipment according to claim 4, characterized in that: The well-shaped air inlet screening assembly also includes a hood, which is arranged on the air inlet and is detachably connected to the air inlet; the hood includes a hood body and a plurality of air inlet holes arranged on the hood body, the air inlet direction of the air inlet holes is downward and forms an angle with the horizontal plane; wherein the size of the angle is 30-50°.

6. The fluidized bed spray coating equipment according to claim 3, characterized in that: Crystal nucleus feed inlets are symmetrically arranged on the side walls of the fluidized bed coating area, and the crystal nucleus feed inlets penetrate the shell, the outer box body and the inner box body.

7. The fluidized bed spray coating equipment according to claim 4, characterized in that: The driving assembly includes a telescopic rod and a driving motor arranged on the telescopic rod. The telescopic rod is arranged at the bottom end inside the spray coating tower and is connected to the grid-type air inlet channel.

8. The fluidized bed spray coating equipment according to claim 1, characterized in that: A first valve is arranged between the solid material collecting device and the solid material collecting area, and a second valve is connected between the solid material collecting device and the outside.

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