Homogenizing device for preparing lithium iron phosphate positive electrode material slurry by solid phase method

Abstract

The utility model discloses a homogenizing device for preparing lithium iron phosphate positive electrode material slurry by a solid phase method, the homogenizing device comprises a tank body, a stirring device and a bubbling device, the stirring device comprises a stirrer, a silica gel wall scraping device is arranged on the edge of a stirring blade of the stirrer, and the silica gel wall scraping device comprises a scraping brush accommodating space and a silica gel scraping brush; the silica gel scraping brush can stretch out of and retract into the scraping brush containing space through telescopic control. The bubbling device comprises four bubblers which are uniformly arranged at the bottom of the tank body and are connected with the air compression pump and the refrigerating system, and the whole homogenizing device is automatically operated through the DCS control system box; according to the device, residual materials on the inner wall of the tank body can be effectively cleaned, the metering error and the proportion imbalance of the materials are reduced, the loss of slurry during material transferring is reduced, the solid content of the slurry is increased, meanwhile, the slurry is cooled by blowing in cold bubbles, the slurry is prevented from sinking to the bottom and being gathered, energy consumption is reduced, and the high-quality slurry is obtained.

Description

Technical Field

[0001] This application relates to the field of equipment technology for material homogenization, and more specifically, to a homogenization apparatus for preparing lithium iron phosphate cathode material slurry by solid-state method. Background Technology

[0002] LiFePO4 cathode material boasts advantages such as high safety, long cycle life, abundant resources, and lower cost, making it the lowest-cost material system among all currently commercially available lithium-ion battery cathode materials. Common preparation methods for LiFePO4 cathode material are mainly liquid-phase and solid-phase methods. Among these, the solid-phase method is widely used in most industrial productions due to its lower cost, simpler process steps, and easier control of product proportions. The main steps of the solid-phase method are homogenization, grinding, drying, sintering, pulverization and sieving, and batch packaging. Homogenization involves sequentially adding lithium sources, iron sources, carbon sources, and additives of different proportions and contents into a homogenizing tank for further micronization and homogenization through a liquid-phase slurry. However, the homogenizing slurry for LiFePO4 cathode material is primarily inorganic, making it prone to adhering to the tank wall surface and easily settling and agglomerating at the bottom, affecting the material quality ratio.

[0003] Traditional homogenizing tanks use a two- or three-bladed agitator to control the rotation speed for uniform mixing. When the slurry is transferred, on the one hand, some slurry remains and adheres to the inner wall of the tank, causing slurry loss, metering errors, and imbalances in the proportions. Even secondary cleaning cannot completely remove the residue, contaminating the next batch of products. On the other hand, the large amount of heat released during slurry mixing can damage the tank and affect the properties of the material, such as particle size, crystallinity, and morphological deformation. In addition, uneven mixing can cause most of the slurry to agglomerate and settle at the bottom of the tank, easily leading to pipe blockage, diaphragm pump overload, and other abnormal hazards, causing equipment failure. Ultimately, it is impossible to produce high-quality and high-efficiency products. Summary of the Invention

[0004] In view of the above, this application provides a homogenization device for preparing lithium iron phosphate cathode material slurry by solid-state method, which effectively cleans the residual material on the tank wall and reduces the imbalance of proportions and material loss.

[0005] This application provides a homogenization device for preparing lithium iron phosphate cathode material slurry by solid-state method, including a tank, a stirring device, and a bubbling device. The stirring device includes a stirrer, and a silicone scraping device is installed on the edge of the stirring blades of the stirrer. The silicone scraping device includes a silicone scraper, which is retractable relative to the stirrer. When the silicone scraper is extended, it contacts the inner wall of the tank. When the silicone scraper is retracted, it does not contact the inner wall of the tank.

[0006] The silicone scraping device also includes a scraper receiving space, which is a closed space located at the edge of the stirring blade. When the silicone scraper retracts, it is located within the scraper receiving space.

[0007] The mixer is a four-blade frame mixer, and the silicone scraper is located on the edge of the frame arms on both sides.

[0008] The mixing device also includes a rotary turbine, and the main shaft of the mixer is connected to the rotary turbine.

[0009] The bubbling device includes a bubbler, an air compressor pump, and a refrigeration system. There are four bubblers, which are evenly arranged at the bottom of the tank and connected to the air compressor pump and the refrigeration system. The air compressor pump and the refrigeration system are placed in a sealable space, and the refrigeration system is used to cool the air entering the air compressor pump.

[0010] This application's device employs a silicone scraper, which avoids the entrainment of residual material during cleaning. Its toothed or arc-shaped design reduces friction between the silicone and the inner wall of the tank, acting as a buffer and minimizing energy loss from the rotating turbine. Simultaneously, the silicone scraper can be extended and retracted within its receiving space via telescopic control. During material homogenization, the scraper remains within this space, reducing friction time between the silicone and the tank wall, extending the device's lifespan, further reducing energy consumption, and preventing slurry adhesion and uneven material dispersion. After homogenization, the silicone scraper is deployed for wall cleaning, effectively removing residual material from the tank wall, reducing metering errors and proportioning imbalances, minimizing slurry transfer losses, and increasing the slurry's solids content.

[0011] Meanwhile, the bubbling device adopts air-cooled bubbling, which not only prevents the slurry from agglomerating and settling to the bottom, ensuring uniform dispersion, but also cools the slurry by introducing cold air bubbles. This avoids damage to the tank due to excessive heat during homogenization and prevents it from affecting the material properties. Bubbling is performed simultaneously with the silicone scraper cleaning the residual material on the inner wall of the tank, preventing secondary settling and wall adhesion during the cleaning process, resulting in more thorough cleaning and more uniform slurry. Furthermore, compared to jacketed water-cooled bubbling devices, the air-cooled bubbling device effectively avoids a large waste of industrial wastewater and reduces energy consumption. Attached Figure Description

[0012] Figure 1 This is a front view of a homogenization apparatus for preparing lithium iron phosphate cathode material slurry using a solid-state method.

[0013] Figure 2 This is a top view of the inside of a homogenizing apparatus for preparing lithium iron phosphate cathode material slurry using a solid-state method.

[0014] The diagram is labeled as follows: 1-Inlet, 2-Outlet, 3-Bubber, 4-Scraper housing, 5-Temperature sensor, 6-DCS control system box, 7-Air compressor pump, 8-Refrigeration system, 9-Rotating turbine, 10-Observation vent, 11-Third platform, 12-Second platform, 13-Silicone scraper, 14-Agitator. Detailed Implementation

[0015] The embodiments of this application will now be described in more detail. This application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to provide a more thorough and complete understanding of the application. It should be understood that the embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0016] The present application will now be described in further detail with reference to the accompanying drawings and embodiments:

[0017] As attached Figure 1 and attached Figure 2 As shown, the homogenizing device used in this embodiment for preparing lithium iron phosphate cathode material slurry by solid-state method includes a tank, a stirring device, and a bubbling device. The top of the tank is located above the third platform 11, the bottom of the tank is located below the second platform 12, and the middle of the tank and the DCS control system box 6 are located above the second platform 12. The observation vent 10 and the feed inlet 1 are located on the two sides of the top of the tank, respectively, and the discharge outlet 2 is located at the center of the bottom of the tank. A temperature sensor 5 is installed in the middle of the tank and is connected to the DCS control system box 6.

[0018] The stirring device includes a rotary turbine 9 and a stirrer 14. The stirrer 14 is a four-blade frame stirrer. A silicone scraping device is installed on the edge of the frame arm on both sides of the stirrer 14. The silicone scraping device includes a scraper receiving space 4 and a silicone scraper 13. The silicone scraper 13 extends and retracts into the scraper receiving space 4 through pneumatic telescopic control. The main shaft of the stirrer 14 passes through the center of the top of the tank and is connected to the rotary turbine 9.

[0019] The bubbling device includes a bubbler 3, an air compressor pump 7, and a refrigeration system 8. There are 4 bubblers 3, which are evenly arranged at the bottom of the tank and connected to the air compressor pump 7 and the refrigeration system 8. The air compressor pump 7 and the refrigeration system 8 are placed in a sealable space, which is placed in the DCS control system box 6.

[0020] The rotary turbine 9 and the bubbling device are both operated automatically through the DCS control system box 6.

[0021] Example:

[0022] The operator first enters the second-level platform 12, opens the DCS control system box 6, and simultaneously turns on the refrigeration system 8. Then, pure water is poured into the tank, and the liquid level, temperature, and quality are observed through the DCS control system box 6. At the same time, the rotary turbine 9 is turned on for stirring. After the system stabilizes, the operator enters the third-level platform 11 and feeds materials into the feed inlet 1 in sequence, and rinses the pipe wall with water as needed. After feeding, the operator turns on the air compressor pump 7 and the bubbler 3 through the DCS system box 6. The operator observes the vent 10 and the bottom glass of the bubbler 3 to determine whether a large number of cold bubbles are generated on the surface of the slurry, to prevent the slurry from settling to the bottom and to lower the slurry temperature, thus ensuring the quality of the slurry. After homogenization, the operator pneumatically opens the scraper receiving space 4 and releases the silicone scraper 13 to scrape and clean the wall. At the same time, the operator transfers the material and observes the slurry sedimentation at the bottom through the bottom glass of the bubbler 3. If sedimentation occurs, the bubbling frequency is increased. After the material transfer is completed, the operator pneumatically closes the scraper receiving space 4 and retracts the silicone scraper 13 into the scraper receiving space 4.

[0023] Before using the device of this application, the slurry had a material loss of 27%, requiring secondary cleaning, resulting in a slurry solid content as low as 32%. After using the device of this application, the slurry had a material loss of only 5%, effectively avoiding secondary cleaning and increasing the slurry solid content to 45%.

[0024] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

Claims

1. A homogenizing device for preparing lithium iron phosphate cathode material slurry by solid phase method, comprising a tank body, a stirring device, a bubbling device, characterized in that: The stirring device comprises a stirrer (14), wherein silica gel wall scraping devices are installed at the edges of the stirring blades of the stirrer (14); the silica gel wall scraping devices comprise silica gel scrapers (13); the silica gel scrapers (13) are retractable relative to the stirrer (14), and the silica gel scrapers (13) are in contact with the inner wall of the tank body when they are extended, and the silica gel scrapers (13) are not in contact with the inner wall of the tank body when they are retracted.

2. The homogenizing device for preparing lithium iron phosphate anode material slurry by solid phase method according to claim 1, characterized in that: The silica gel wall scraping devices further comprise scraper containing spaces (4), which are closed spaces and are arranged at the edges of the stirring blades, and the silica gel scrapers (13) are located in the scraper containing spaces (4) when they are retracted. 3.The homogenizing device for preparing lithium iron phosphate cathode material slurry by solid phase method according to any one of claims 1 or 2, characterized in that: The stirrer (14) is a four-blade frame stirrer, and the silica gel wall scraping devices are arranged at the edges of the frame arms on both sides.

4. The homogenizing device for preparing lithium iron phosphate cathode material slurry by solid phase method according to any one of claims 1 or 2, characterized in that: The bubbling device comprises bubblers (3), an air compression pump (7), and a refrigeration system (8); the bubblers (3) are four in number and are uniformly arranged at the bottom of the tank body and are connected with the air compression pump (7) and the refrigeration system (8); the air compression pump (7) and the refrigeration system (8) are arranged in a closable space, and the refrigeration system (8) is used for refrigerating the air entering the air compression pump (7).

Images