Continuous synthesis reactor and preparation method of lithium manganese iron phosphate

Abstract

The continuous synthesis reactor comprises a support, a reaction tower is erected on the support, a center pipe penetrating through the reaction tower vertically is fixed to the center of the reaction tower, an inner pipe is arranged in the center pipe, a discharging bin is arranged below the reaction tower, and one side of the discharging bin is connected with a discharging pipe tangent to the discharging bin; an upper flow guide cover and a lower flow guide cover are respectively arranged above and below a central pipe of the reaction tower, an upper spray head is arranged below the upper flow guide cover, and a lower spray head is arranged on the lower flow guide cover; compared with the prior art, through integrated continuous design, accurate environment control and dynamic parameter adjustment, comprehensive optimization of the product in the aspects of consistency, performance, cost and production efficiency is achieved.

Description

Technical Field

[0001] This invention relates to the field of compound reactor technology, specifically to a continuous synthesis reactor and preparation method for lithium manganese iron phosphate. Background Technology

[0002] Lithium manganese iron phosphate (LMFP), as an upgraded material of lithium iron phosphate, significantly improves the energy density by introducing manganese, raising its voltage platform from 3.4V to around 4.1V. Simultaneously, it inherits the advantages of lithium iron phosphate, such as high safety, long cycle life, and relatively low cost, and is considered one of the ideal cathode materials for next-generation power batteries and large-scale energy storage systems, possessing extremely important commercial prospects.

[0003] However, the synthesis of LMFP faces two major challenges: First, manganese and iron need to form a uniform solid solution at the atomic scale. Uneven distribution leads to the formation of LiMnPO4 and LiFePO4 impurities, resulting in unstable voltage plateaus and reduced capacity. Second, its intrinsic electronic and ionic conductivity is low, and the dissolution of Mn³⁺ in the electrolyte and the Jameer-Taylor effect cause degradation in cycling performance. Therefore, efficient carbon coating and nano-scale design are essential.

[0004] Currently, the synthesis of LMFP mainly relies on traditional batch operations, where solid raw materials such as iron, manganese, lithium, and phosphorus sources are mechanically ball-milled and mixed with a carbon source, followed by prolonged high-temperature sintering (typically >600°C) in a tube furnace or roller kiln under an inert atmosphere. This batch production requires cooling, unloading, and reheating after each batch, resulting in long cycles, high energy consumption, and difficulties in mass transfer during solid-phase reactions, making it difficult to ensure atomic-level uniform distribution of Mn / Fe and easily generating impurity phases. Physically mixed carbon sources are difficult to form a uniform and complete coating layer, leading to suboptimal conductive network construction. Prolonged high-temperature sintering easily causes excessive particle growth and agglomeration, which is detrimental to nano-sizing and lithium-ion diffusion.

[0005] Therefore, it is necessary to provide a continuous synthesis reactor and preparation method for lithium manganese iron phosphate to solve the problems mentioned in the background art. Summary of the Invention

[0006] To achieve the above objectives, the present invention provides the following technical solution: a continuous synthesis reactor for lithium manganese iron phosphate, comprising a support frame, a reaction tower mounted on the support frame, a central tube fixed at the center of the reaction tower running through it from top to bottom, an inner tube inside the central tube, a discharge hopper below the reaction tower, and a discharge pipe tangential to one side of the discharge hopper;

[0007] The reaction tower has an upper guide shroud and a lower guide shroud installed above and below the central tube, respectively. An upper nozzle is installed below the upper guide shroud, and a lower nozzle is installed on the lower guide shroud.

[0008] Furthermore, the reaction tower contains multiple coils of heating tubes distributed along its height.

[0009] Furthermore, a discharge fan tangential to the discharge hopper is connected to one side of the discharge hopper.

[0010] Furthermore, the central tube is divided into upper and lower sections at the upper guide shroud. The upper section is connected to the upper nozzle, and the lower section is connected to the upper and lower guide shrouds. A guide fan is connected to the lower end of the central tube.

[0011] Furthermore, an upper connecting plate is fixedly sleeved on the outer wall of the central tube below the upper guide shroud, and multiple upper nozzles are circumferentially distributed and hinged to the edge of the upper connecting plate;

[0012] A lower connecting plate is fixedly sleeved on the outer wall of the central tube above the lower guide shroud, and multiple lower nozzles are circumferentially distributed and hinged to the edge of the lower connecting plate.

[0013] Furthermore, an upper sliding disc is slidably sleeved on the outer wall of the central tube below the upper connecting disc, and each upper nozzle is hinged to the upper sliding disc via an upper push rod;

[0014] A lower sliding disc is slidably sleeved on the outer wall of the central tube above the lower connecting disc, and each lower nozzle is hinged to the lower sliding disc via a lower push rod.

[0015] Furthermore, lead screws are rotatably installed on both sides of the central tube. The lead screws are threadedly connected to the upper and lower sliding discs. The lower end of the lead screw extends through to the bottom of the reaction tower and is connected to a lead screw motor.

[0016] Furthermore, a ring of side air inlet grooves is distributed in the middle of the reaction tower, and a side air inlet pipe tangential to one side of each side air inlet groove is connected to it.

[0017] Furthermore, an inner layer is fixed to the inner wall of the reaction tower, and multiple guide plates penetrating the inner layer are rotatably arranged in the inner layer between the upper and lower guide hoods;

[0018] The side air intake slot is rotatably fitted with a turntable, and each of the guide plates is hinged to the turntable via a connecting rod.

[0019] A method for the continuous synthesis of lithium manganese iron phosphate, comprising:

[0020] S1: Activate the multi-coil heating tubes distributed along the height direction inside reaction tower 2 to establish a precise temperature gradient for the reaction tower:

[0021] Upper temperature zone: 200-400°C

[0022] Central temperature zone: 500-700°C

[0023] Lower temperature zone: 600-800°C

[0024] S2: Start the guide fan to pump inert gas into the lower section of the central tube, and the gas is blown out from the upper and lower guide shrouds;

[0025] S3: The precursor solution is delivered to the upper nozzle through the upper section of the central tube; the glucose solution is delivered to the lower nozzle through the inner tube. The upper and lower nozzles atomize the solution into micron-sized droplets and spray them out.

[0026] S4: Under the guidance of airflow and temperature gradient, it goes through three stages:

[0027] In the upper temperature zone: the solvent evaporates, the precursor salts decompose and undergo preliminary reactions to form the LMFP intermediate;

[0028] In the middle temperature range: intermediate crystallizes to form a complete olivine-type LMFP crystal;

[0029] In the lower temperature zone: glucose is pyrolyzed, and the generated amorphous carbon is uniformly coated on the surface of LMFP particles, completing in-situ carbon coating and optimizing the crystal structure simultaneously.

[0030] S5: Adjust nozzle angle: Start the lead screw motor, drive the lead screw to rotate, drive the upper and lower sliding plates to move, and then change the spray angle of all upper and lower nozzles synchronously through the upper and lower push rods;

[0031] Adjusting the central vortex: By adjusting the turntable, the tilt angle of all guide vanes is changed synchronously through the linkage mechanism. Inert gas enters the side intake slot tangentially through the side intake pipe, and then forms an adjustable vortex through the guide vanes.

[0032] S6: The synthesized LMFP powder falls into the discharge hopper. The discharge fan uses pneumatic conveying to continuously transport the product powder to the collection system through the tangentially connected discharge pipe.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] In this invention, multiple independent processes such as precursor drying, decomposition, crystallization, and carbon coating are integrated into a single reaction tower. Compared to traditional batch reactors, this eliminates the intervals and interruptions between batches, significantly increasing production capacity. Furthermore, the integrated design reduces material transfer, heating, and cooling processes between different devices, significantly reducing heat loss and operating energy consumption. Simultaneously, the continuous flow of materials within a closed system avoids contamination and losses caused by material exposure and transfer in traditional processes, ensuring high product purity.

[0035] In this invention, multiple coils of heating tubes distributed along the height of the reaction tower create a precisely controllable temperature field from top to bottom. This allows the material to sequentially complete evaporation, reaction, crystallization, and coating at an optimal temperature sequence, ensuring the integrity and high crystallinity of the olivine crystal structure.

[0036] The precursor and carbon source solution are atomized and thoroughly mixed by circumferentially distributed upper and lower nozzles, achieving uniform dispersion of the materials at the molecular level. Inert gas is introduced into the lower section of the central tube by a guide fan, forming a protective gas curtain through the upper and lower guide hoods, providing an oxygen-free environment for the entire reaction process. This effectively prevents Fe²⁺ and Mn²⁺ from being oxidized into trivalent ions, improving the material's cycle life and structural stability.

[0037] In this invention, the position of the upper and lower sliding discs can be adjusted synchronously by driving the lead screw motor, and then the spray angle of all nozzles can be changed by the upper and lower push rods. This allows for precise control of the droplet trajectory, mixing intensity, and residence time in the reaction zone without stopping the machine, in order to adapt to different formulations or optimize particle morphology (such as solid spheres or porous spheres).

[0038] The side air inlet slots and adjustable guide vanes allow the angle of the guide vanes to be changed synchronously by rotating the turntable, thereby generating an adjustable swirling flow in the middle of the reaction tower. A strong swirling flow can prolong the residence time and promote complete reaction, while a weak swirling flow can accelerate the discharge and prevent over-sintering. This provides a key means for optimizing reaction kinetics. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of a continuous synthesis reactor for lithium manganese iron phosphate;

[0040] Figure 2 This is a schematic diagram of the internal structure of the reaction tower;

[0041] Figure 3 This is a schematic cross-sectional view of the middle section of the reaction tower.

[0042] Figure 4 This is a schematic diagram of the structure at the lower fairing.

[0043] Figure 5 This is a schematic diagram of the cross-sectional structure of the side air intake slot;

[0044] In the diagram: 1. Support frame; 2. Reaction tower; 21. Inner layer; 3. Central tube; 31. Inner tube; 32. Guide fan; 4. Discharge hopper; 41. Discharge pipe; 42. Discharge fan; 5. Upper guide hood; 51. Upper connecting plate; 52. Upper nozzle; 53. Upper sliding plate; 54. Upper push rod; 6. Lower guide hood; 61. Lower connecting plate; 62. Lower nozzle; 63. Lower sliding plate; 64. Lower push rod; 7. Side air inlet slot; 71. Side air inlet pipe; 72. Guide plate; 73. Turntable; 74. Connecting rod; 8. Lead screw; 81. Lead screw motor. Detailed Implementation

[0045] Please see Figures 1-5 In this embodiment of the invention, the continuous synthesis reactor for lithium manganese iron phosphate includes a support 1, on which a reaction tower 2 is mounted. A central tube 3 is fixed in the center of the reaction tower 2, running through it from top to bottom. An inner tube 31 is installed inside the central tube 3. Below the reaction tower 2 is a discharge hopper 4, and a discharge pipe 41 tangential to the discharge hopper 4 is connected to one side of the discharge hopper 4.

[0046] The reaction tower 2 has an upper guide shroud 5 and a lower guide shroud 6 respectively installed on the upper and lower parts of the central pipe 3. An upper nozzle 52 is installed below the upper guide shroud 5, and a lower nozzle 62 is installed on the lower guide shroud 6.

[0047] In this embodiment, multiple heating tubes are distributed along the height direction inside the reaction tower 2.

[0048] In this embodiment, a discharge fan 42 tangential to the discharge hopper 4 is connected to one side of the discharge hopper 4.

[0049] The upper nozzle 52 is connected to the central tube 3, and the lower nozzle 62 is connected to the inner tube 31. A precursor solution (providing lithium, iron, manganese and phosphorus sources) is introduced into the central tube 3, and a glucose solution (providing carbon source) is introduced into the inner tube 31. The upper nozzle 52 atomizes the precursor solution into micron-sized droplets, and the lower nozzle 62 atomizes the glucose solution into micron-sized droplets. The two nozzles spray at a specific angle, so that the two droplets collide and mix fully in the reaction tower.

[0050] Multiple heating tubes are distributed along the height of reaction tower 2, creating a precise and controllable temperature gradient from top to bottom within reaction tower 2.

[0051] Upper temperature zone (200-400°C): After the atomized droplets enter, the solvent is instantly evaporated, the precursor salts decompose and undergo preliminary solid-phase reaction to form amorphous or low-crystallinity LMFP intermediates.

[0052] In the middle temperature range (500-700°C): the intermediate crystallizes at higher temperatures to form a complete olivine-type LMFP crystal structure;

[0053] Lower temperature zone (600-800°C): In this high-temperature zone, glucose is completely pyrolyzed to form amorphous carbon, which is uniformly coated on the surface of the newly formed LMFP particles, completing in-situ carbon coating. At the same time, the crystal form of LMFP is further optimized.

[0054] The powder particles that have completed the reaction fall into the discharge hopper 4 at the bottom. The discharge pipe 41 uses the discharge fan 42 to pneumatically convey the powder material by high-speed airflow. The cyclone separation principle can be used to ensure that the material is discharged smoothly and to prevent the powder from accumulating and clogging at the outlet.

[0055] In this embodiment, the central tube 3 is divided into upper and lower sections at the upper guide shroud 5. The upper section is connected to the upper nozzle 52, and the lower section is connected to the upper guide shroud 5 and the lower guide shroud 6. The lower end of the central tube 3 is connected to the guide fan 32.

[0056] In other words, the upper section of the central tube 3 is used to transport the precursor solution into the upper nozzle 52, while the lower section is used to provide guiding gas to the upper guide shroud 5 and the lower guide shroud 6.

[0057] The guide fan 32 introduces inert gases such as nitrogen and argon, which are blown out from the upper and lower guide hoods. This ensures the smooth atomization and initial distribution of the precursor droplets and glucose solution, and creates a protective atmosphere for the reaction process. It maintains an inert environment throughout the reaction path to prevent material oxidation. It can also guide and optimize the airflow pattern inside the tower, control the movement trajectory and residence time of the particles, and achieve gentle discharge.

[0058] In this embodiment, an upper connecting plate 51 is fixedly sleeved on the outer wall of the central tube 3 below the upper guide shroud 5, and a plurality of upper nozzles 52 are circumferentially distributed and hinged to the edge of the upper connecting plate 51.

[0059] A lower connecting plate 61 is fixedly sleeved on the outer wall of the central tube 3 above the lower guide shroud 6, and multiple lower nozzles 62 are circumferentially distributed and hinged to the edge of the lower connecting plate 61.

[0060] By uniformly distributing multiple nozzles around the circumference, the precursor solution and carbon source solution are simultaneously and equally sprayed onto the entire cross-section of the reaction tower, creating a three-dimensional reaction space. The droplets of the two materials can cross, collide and mix to the maximum extent in the tower space, achieving a high degree of uniformity at the microscale.

[0061] In this embodiment, an upper sliding disk 53 is slidably sleeved on the outer wall of the central tube 3 below the upper connecting disk 51, and each upper nozzle 52 is hinged to the upper sliding disk 53 by an upper push rod 54.

[0062] A lower sliding disc 63 is slidably sleeved on the outer wall of the central tube 3 above the lower connecting disc 61, and each of the lower nozzles 62 is hinged to the lower sliding disc 63 by a lower push rod 64.

[0063] In this embodiment, lead screws 8 are rotatably arranged on both sides of the central tube 3. The lead screws 8 are threadedly connected to the upper sliding plate 53 and the lower sliding plate 63. The lower end of the lead screw 8 extends through to the bottom of the reaction tower 2 and is connected to a lead screw motor 81.

[0064] The screw motor 81 drives the screw 8 to rotate. The upper sliding plate 53 and the lower sliding plate 63, which are threadedly connected to the screw 8, slide up or down as the screw 8 rotates. This motion is converted into the oscillating motion of the nozzle by the upper push rod 54 and the lower push rod 64.

[0065] Reaction conditions can be rapidly optimized and adjusted based on different precursor formulations, concentrations, or target particle sizes: the angle between the upper nozzle 52 / lower nozzle 62 and the central tube 3 can be reduced to enhance the downward mainstream field and shorten the residence time. Conversely, the angle between the upper nozzle 52 / lower nozzle 62 and the central tube 3 can be increased to extend the droplet swirling path in the reaction zone and prolong the reaction and residence time. This adjustability facilitates fine-tuning in process development and large-scale production.

[0066] By adjusting the angle, the optimal position for maximizing the collision and mixing efficiency of the precursor and carbon source droplets can be achieved, resulting in more uniform carbon coating at the molecular level and directly improving the conductivity of LMFP products. Adjusting the angle can also change the flight path of the droplets in the high-temperature region, thereby precisely controlling their residence time to generate a more ideal crystal structure and particle size distribution.

[0067] If different specifications of LMFP need to be produced (for example, for different particle size / morphology requirements of power batteries or energy storage batteries), simply call the preset motor program, and the nozzle can be automatically adjusted to the corresponding optimal angle to achieve rapid product switching.

[0068] In this embodiment, a ring of side air inlet grooves 7 is distributed in the middle of the reaction tower 2, and a side air inlet pipe 71 tangential to one side of the side air inlet grooves 7 is connected to it.

[0069] In this embodiment, an inner layer 21 is fixed to the inner wall of the reaction tower 2, and multiple guide plates 72 that penetrate the inner layer 21 are rotatably arranged in the inner layer 21 between the upper guide shroud 5 and the lower guide shroud 6.

[0070] In this embodiment, the side air intake groove 7 is rotatably fitted with a turntable 73, and each of the guide plates 72 is hinged to the turntable 73 via a connecting rod 74.

[0071] It can actively generate a rotating airflow with controllable intensity and direction in the central reaction zone of reaction tower 2, thereby achieving precise management of the movement trajectory, residence time, and temperature uniformity of the reactants:

[0072] Gas (such as inert nitrogen) enters the side inlet slot 7 tangentially through the side inlet pipe 71. This tangential airflow naturally forms a rotating airflow in the annular slot. The rotating airflow enters the main reaction zone through the adjustable angle guide plate 72, transforming the straight tangential flow into a uniform and powerful three-dimensional swirling flow that fills the entire cross-section of the reaction tower.

[0073] Rotating the turntable 73, the tilt angle of all guide plates 72 can be changed synchronously and uniformly through the connecting rod 74, thereby changing the intensity and flow pattern of the swirling flow. By adjusting the angle of the guide plates 72, the residence time of particles in the critical reaction zone can be precisely controlled: a large angle of the guide plate 72 results in a large swirling flow, with particles spiraling downwards, a longer path, and a longer residence time, which is suitable for process conditions requiring sufficient reaction and crystallization; a small angle of the guide plate 72 results in a weak swirling flow, with particles falling almost vertically, a shorter path, and a shorter residence time, which is suitable for process conditions that prevent over-reaction or sintering.

[0074] In addition, the tangentially entering swirling flow forms a high-speed rotating air curtain near the wall of reaction tower 2. The swirling flow close to the tower wall prevents particles from depositing and adhering on the wall, and produces a continuous sweeping effect on the tower wall and the inner layer 21 surface, which alleviates the problems of fouling and clogging in the reactor and ensures continuous operation.

[0075] A method for the continuous synthesis of lithium manganese iron phosphate, comprising:

[0076] S1: Activate the multi-coil heating tubes distributed along the height direction inside reaction tower 2 to establish a precise temperature gradient for reaction tower (2):

[0077] Upper temperature zone: 200-400°C

[0078] Central temperature zone: 500-700°C

[0079] Lower temperature zone: 600-800°C

[0080] S2: Start the guide fan (32) to pump inert gas (such as nitrogen or argon) into the lower section of the central tube (3). The gas is blown out from the upper guide hood (5) and the lower guide hood (6) to build an oxygen-free inert protective atmosphere for the entire reaction path and form a stable downward plunger flow field inside the reaction tower (2) to provide a stable gas environment for the atomization zone.

[0081] S3: The precursor solution is transported to the upper nozzle (52) through the upper section of the central tube (3): The glucose solution is transported to the lower nozzle (62) through the inner tube (31). The upper nozzle (52) and the lower nozzle (62) atomize the solution into micron-sized droplets and spray them out, ensuring that the droplets are evenly dispersed throughout the entire cross section of the reaction tower (2), and the two droplets collide and mix fully in the space inside the tower.

[0082] S4: Under the guidance of airflow and temperature gradient, it goes through three stages:

[0083] In the upper temperature zone: the solvent evaporates, the precursor salts decompose and undergo preliminary reactions to form the LMFP intermediate;

[0084] In the middle temperature range: intermediate crystallizes to form a complete olivine-type LMFP crystal;

[0085] In the lower temperature zone: glucose is pyrolyzed, and the generated amorphous carbon is uniformly coated on the surface of LMFP particles, completing in-situ carbon coating and optimizing the crystal structure simultaneously.

[0086] S5: Adjust the nozzle angle: Start the screw motor (81) to drive the screw (8) to rotate, which will drive the upper sliding plate (53) and the lower sliding plate (63) to move, and then change the spray angle of all the upper nozzles (52) and the lower nozzles (62) synchronously through the upper push rod (54) and the lower push rod (64) to control the residence time and mixing efficiency.

[0087] Adjusting the central vortex: By adjusting the turntable (73), the tilt angle of all guide plates (72) is changed synchronously through the connecting rod (74) mechanism. The inert gas enters the side intake groove (7) tangentially through the side intake pipe (71), and then forms an adjustable vortex through the guide plate (72). The strong vortex (large angle of guide plate (72)) can prolong the residence time and promote the reaction, while the weak vortex (small angle of guide plate (72)) can shorten the residence time and prevent over-sintering. The vortex also plays the role of flushing the inner layer (21) wall and preventing scaling.

[0088] S6: The synthesized LMFP powder falls into the discharge hopper (4), and the discharge fan (42) uses pneumatic conveying to continuously transport the product powder to the collection system through the tangentially connected discharge pipe (41), effectively preventing the powder from accumulating and clogging at the outlet.

[0089] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A continuous synthesis reactor for lithium manganese iron phosphate, characterized in that, Includes a support (1), on which a reaction tower (2) is mounted, and a central tube (3) is fixed in the center of the reaction tower (2) and runs through it from top to bottom. An inner tube (31) is installed inside the central tube (3). Below the reaction tower (2) is a discharge hopper (4), and a discharge pipe (41) tangential to the discharge hopper (4) is connected to one side of the discharge hopper (4). The reaction tower (2) has an upper guide shroud (5) and a lower guide shroud (6) respectively installed on the center pipe (3). An upper nozzle (52) is installed below the upper guide shroud (5), and a lower nozzle (62) is installed on the lower guide shroud (6).

2. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 1, characterized in that, The reaction tower (2) has multiple heating tubes distributed along the height direction.

3. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 1, characterized in that, The discharge hopper (4) is connected to a discharge fan (42) that is tangential to it.

4. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 1, characterized in that, The central tube (3) is divided into upper and lower sections at the upper guide shroud (5). The upper section is connected to the upper nozzle (52), and the lower section is connected to the upper guide shroud (5) and the lower guide shroud (6). The lower end of the central tube (3) is connected to a guide fan (32).

5. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 1, characterized in that, The outer wall of the central tube (3) below the upper guide shroud (5) is fixedly fitted with an upper connecting plate (51), and multiple upper nozzles (52) are circumferentially distributed and hinged to the edge of the upper connecting plate (51); The lower connecting plate (61) is fixedly sleeved on the outer wall of the central tube (3) above the lower guide shroud (6), and the multiple lower nozzles (62) are circumferentially distributed and hinged to the edge of the lower connecting plate (61).

6. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 5, characterized in that, The outer wall of the central tube (3) below the upper connecting plate (51) is slidably fitted with an upper sliding plate (53), and each upper nozzle (52) is hinged to the upper sliding plate (53) by an upper push rod (54); The outer wall of the central tube (3) above the lower connecting plate (61) is slidably fitted with a lower sliding plate (63), and each of the lower nozzles (62) is hinged to the lower sliding plate (63) by a lower push rod (64).

7. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 6, characterized in that, The central tube (3) is rotatably provided with lead screws (8) on both sides. The lead screws (8) are threadedly connected to the upper sliding plate (53) and the lower sliding plate (63). The lower end of the lead screws (8) extends through to the bottom of the reaction tower (2) and is connected to a lead screw motor (81).

8. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 1, characterized in that, The reaction tower (2) has a ring of side air inlet grooves (7) in the middle, and a side air inlet pipe (71) tangential to the side of the side air inlet groove (7).

9. The continuous synthesis reactor for lithium manganese iron phosphate according to claim 1, characterized in that, The inner wall of the reaction tower (2) is fixed with an inner layer (21), and multiple guide plates (72) penetrating the inner layer (21) are rotatably arranged in the inner layer (21) between the upper guide shroud (5) and the lower guide shroud (6). The side air intake groove (7) is rotatably fitted with a turntable (73), and each of the guide plates (72) is hinged to the turntable (73) via a connecting rod (74).

10. A method for the continuous synthesis of lithium manganese iron phosphate, comprising using a continuous synthesis reactor for lithium manganese iron phosphate according to any one of claims 1-9, characterized in that, include: S1: Activate the multi-coil heating tubes distributed along the height direction inside reaction tower 2 to establish a precise temperature gradient for reaction tower (2): Upper temperature zone: 200-400°C Central temperature zone: 500-700°C Lower temperature zone: 600-800°C S2: Start the guide fan (32) to pump inert gas into the lower section of the central pipe (3), and the gas is blown out from the upper guide shroud (5) and the lower guide shroud (6); S3: The precursor solution is transported to the upper nozzle (52) through the upper section of the central tube (3); the glucose solution is transported to the lower nozzle (62) through the inner tube (31). The upper nozzle (52) and the lower nozzle (62) atomize the solution into micron-sized droplets and spray them out respectively. S4: Under the guidance of airflow and temperature gradient, it goes through three stages: In the upper temperature zone: the solvent evaporates, the precursor salts decompose and undergo preliminary reactions to form the LMFP intermediate; In the middle temperature range: intermediate crystallizes to form a complete olivine-type LMFP crystal; In the lower temperature zone: glucose is pyrolyzed, and the generated amorphous carbon is uniformly coated on the surface of LMFP particles, completing in-situ carbon coating and optimizing the crystal structure simultaneously. S5: Adjust the nozzle angle: Start the screw motor (81), drive the screw (8) to rotate, drive the upper sliding plate (53) and the lower sliding plate (63) to move, and then change the spray angle of all upper nozzles (52) and lower nozzles (62) synchronously through the upper push rod (54) and the lower push rod (64); Adjusting the central vortex: By adjusting the turntable (73), the tilt angle of all guide plates (72) is changed synchronously through the linkage (74) mechanism. The inert gas enters the side intake slot (7) tangentially through the side intake pipe (71) and then forms an adjustable vortex through the guide plate (72). S6: The synthesized LMFP powder falls into the discharge hopper (4), and the discharge fan (42) uses pneumatic conveying to continuously transport the product powder to the collection system through the tangentially connected discharge pipe (41).

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