Lithium iron phosphate kiln sintering device

Abstract

The utility model discloses a lithium iron phosphate kiln sintering device which comprises a heating area provided with an exhaust pipeline, an atmosphere detection device is arranged on the exhaust pipeline, the lithium iron phosphate kiln sintering device further comprises a central control system, and the central control system is connected with the atmosphere detection device. And the product modification device is adjusted according to detection data of the atmosphere detection device. According to the utility model, the atmosphere of the kiln is monitored through the atmosphere detection device, and the product modification device is adjusted through the central control system to modify the product, so that the performance and the product stability of the lithium iron phosphate positive electrode material are improved.

Description

Technical Field

[0001] The utility model relates to a kiln sintering device, in particular to a lithium iron phosphate kiln sintering device capable of improving product quality. Background Art

[0002] In recent years, with the rapid development of the new energy industry, the preparation of lithium iron phosphate positive electrode materials has also faced more challenges.

[0003] Kiln sintering is the most critical process in the production and preparation of lithium iron phosphate. It mainly reacts iron phosphate and lithium carbonate to produce lithium iron phosphate. During kiln sintering, the gas atmosphere of the kiln will have a great impact on the performance of the product. When the concentration of reducing gas in the heating zone is too high, it is very easy to cause iron phosphide to be produced. When the concentration of reducing gas is too low, it will cause high iron dissolution in the finished product. Since the gas atmosphere of the kiln is difficult to control, the performance of the products prepared by it cannot be guaranteed. Utility Model Content

[0004] Purpose of the utility model: The purpose of the utility model is to provide a lithium iron phosphate kiln sintering device that can improve the performance of lithium iron phosphate positive electrode materials.

[0005] Technical solution: The lithium iron phosphate kiln sintering device described in the utility model includes a temperature rising zone equipped with an exhaust duct, an atmosphere detection device is provided on the exhaust duct, and the lithium iron phosphate kiln sintering device also includes a central control system, which is connected to the atmosphere detection device to adjust the product modification device according to the detection data of the atmosphere detection device.

[0006] By monitoring the kiln atmosphere through the atmosphere detection device and adjusting the kiln sintering atmosphere through the central control system, the kiln gas atmosphere can be controlled to improve the performance and product stability of lithium iron phosphate positive electrode materials.

[0007] The exhaust duct includes a plurality of sub-exhaust pipes arranged along the axial direction of the heating zone, and each of the sub-exhaust pipes is provided with an atmosphere detection device. The temperature of the heating zone gradually increases from the front to the back, and the gas components generated in each area of ​​the heating zone are different. By installing the atmosphere detection device on each sub-exhaust pipe, the sintering state of different areas of the heating zone can be detected, thereby obtaining more comprehensive and accurate gas atmosphere data, which is conducive to the central control system adjusting the product modification device to the appropriate parameters.

[0008] The product modification device is a methanol spray device. Methanol decomposes and carbonizes when heated, and can form a carbon film on the surface of lithium iron phosphate, which improves the conductivity of the material and reduces the polarization risk of the battery; at the same time, methanol carbon coating also provides an electron tunnel for the lithium iron phosphate positive electrode material, compensating for the charge balance of lithium ions during the insertion and extraction process, which has a significant effect on improving product performance.

[0009] The central control system adjusts the spray time and spray rate of the methanol spray device according to the detection data of the atmosphere detection device. The central control system collects and records the detection data of the atmosphere detection device. In the early stage, the spray time and rate of methanol are manually adjusted through the central control system, and through repeated verification and debugging, a model between the kiln atmosphere and the parameters of the methanol spray device is established. After continuous optimization, the model can eventually completely replace manual debugging. The central control system automatically adjusts the spray time and spray rate of the methanol spray device according to the detection data of the atmosphere detection device to modify the product.

[0010] A constant temperature zone and a cooling zone are arranged in sequence behind the heating zone, and the methanol spray device is arranged in the cooling zone. The temperature of the cooling zone is gradually reduced by water cooling, and the temperature of the material coming out is generally lower than 60°C; the temperature of the constant temperature zone is preferably set at about 780°C, which is conducive to the smooth growth and agglomeration of grains to form secondary grains. Methanol will be efficiently decomposed at a temperature of 400°C or above, but if the temperature is too high, methanol will gasify quickly, which will have a greater impact on the product atmosphere and worsen the modification effect of the product. Setting the temperature of the position where the methanol spray device is located above 400°C and below 500°C can allow methanol to be fully decomposed and carbonized by heat, and will not have a significant impact on the gas atmosphere of the kiln, which is conducive to the formation of a carbon coating on the surface of the material by methanol to improve the electrical conductivity of the material.

[0011] The methanol spraying device comprises a methanol storage tank, a pump and a spray head which are connected in sequence. The central control system controls the opening and closing of the pump and the flow rate so as to control the spraying time and spraying rate of the methanol.

[0012] Beneficial effects: Compared with the prior art, the utility model has the following advantages: 1. By arranging an atmosphere detection device on the exhaust duct in the heating zone, the sintering state of the kiln can be monitored in real time, and the central control system can timely modify the product according to the detection data to ensure product quality; 2. The methanol spray device is installed in the cooling zone, and the central control system can adjust the spray rate and time of the methanol spray device to modify the material well. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0014] Figure 2 It is a schematic diagram of the specific structure of the utility model. DETAILED DESCRIPTION

[0015] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0016] Example 1: Figures 1 to 2As shown, the lithium iron phosphate kiln sintering device described in the utility model includes an inlet displacement chamber 5, a temperature rising zone 1, a constant temperature zone 2, a temperature falling zone 3 and an outlet displacement chamber 6 in sequence. The temperature rising zone 1 is equipped with an exhaust pipe 11, and the exhaust pipe 11 includes sub-exhaust pipes arranged axially along the temperature rising zone 1, and the sub-exhaust pipes are equipped with an atmosphere detection device 12, and the temperature falling zone 3 is equipped with a methanol spray device 31.

[0017] The lithium iron phosphate kiln sintering device also includes a central control system 4, which is connected to the atmosphere detection device 12 and the methanol spray device 31. The central control system 4 includes a PLC industrial computer 41 and a display module 42. The central control system 4 adjusts the spray time and spray rate of the methanol spray device 31 according to the detection data of the atmosphere detection device 12. The central control system 4 collects and records the detection data of the atmosphere detection device 12. In the early stage, the spray time and rate of methanol are manually adjusted through the central control system 4, and a model between the kiln atmosphere and the parameters of the methanol spray device 12 is established through repeated verification and debugging. The model is continuously optimized and can eventually completely replace manual debugging. The central control system 4 automatically adjusts the spray time and spray rate of the methanol spray device 31 according to the detection data of the atmosphere detection device 12, and performs modification on the product, which greatly saves manpower and time costs and improves product quality stability and production efficiency.

[0018] The methanol spraying device 31 includes a methanol storage tank 311, a pump 312 and a spray head 313 connected in sequence. The central control system 4 controls the pump 312 of the methanol spraying device 31, thereby controlling the flow rate and rate of the methanol spraying. The methanol spraying device 31 is set at 400°C in the cooling zone 3.

[0019] Specifically, the material reaction stage is carried out in the temperature rising zone 1, and there are many reactions such as carbon source decomposition, lithium ion embedding and primary grain generation. A large amount of gas will be generated during the reaction. When the reducing gas content is too high or too low, the atmosphere detection device 12 will feed back the monitoring data to the central control system 4. The central control system 4 matches the appropriate kiln sintering parameters according to the model to optimize the atmosphere and product performance.

[0020] What occurs in constant temperature zone 2 is the process of grain growth and agglomeration to form secondary grains, and the set temperature is 780°C.

[0021] The cooling zone 3 gradually lowers the temperature by water cooling. Since the material will not produce a large reaction during the cooling stage, it is suitable for modification treatment. The central control system 4 matches the appropriate methanol spraying time and spraying rate according to the detection data of the atmosphere detection device 12, and controls the methanol spraying device 31 to spray methanol to the material, so that a carbon coating is formed on the surface of the material to improve the conductive properties of the final product.

[0022] Example 2: The difference between this example and Example 1 is that the methanol spraying device 31 is arranged at the 480°C position of the cooling zone 3.

Claims

1. A lithium iron phosphate kiln sintering device, comprising a heating zone (1) equipped with an exhaust pipe (11), characterized in that: The exhaust duct (11) is provided with an atmosphere detection device (12), and the lithium iron phosphate kiln sintering device also includes a central control system (4), and the central control system (4) is connected to the atmosphere detection device (12) to adjust the product modification device according to the detection data of the atmosphere detection device (12).

2. The lithium iron phosphate kiln sintering device according to claim 1, characterized in that: The exhaust duct (11) comprises a plurality of sub-exhaust pipes arranged along the axial direction of the temperature rising zone (1), and each of the sub-exhaust pipes is provided with an atmosphere detection device (12).

3. The lithium iron phosphate kiln sintering device according to claim 1, characterized in that: The product modification device is a methanol spraying device (31).

4. The lithium iron phosphate kiln sintering device according to claim 3, characterized in that: The central control system (4) adjusts the spraying time and spraying rate of the methanol spraying device (31) according to the detection data of the atmosphere detection device (12).

5. The lithium iron phosphate kiln sintering device according to claim 3, characterized in that: A constant temperature zone (2) and a cooling zone (3) are arranged in sequence behind the heating zone (1), and the methanol spraying device (31) is arranged in the cooling zone (3).

6. The lithium iron phosphate kiln sintering device according to claim 5, characterized in that: The temperature at the location where the methanol spraying device (31) is located is above 400° C. and below 500° C.

7. The lithium iron phosphate kiln sintering device according to claim 3, characterized in that: The methanol spraying device (31) comprises a methanol storage tank (311), a pump (312) and a spray head (313) which are connected in sequence.

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