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CN-121990544-A - Manganese iron phosphate material and preparation method and application thereof

CN121990544ACN 121990544 ACN121990544 ACN 121990544ACN-121990544-A

Abstract

The application belongs to the technical field of secondary batteries, and discloses a manganese iron phosphate material, a preparation method and application thereof, wherein the preparation method of the manganese iron phosphate material comprises the following steps of S1, mixing an iron salt solution, a manganese salt solution, a phosphoric acid solution and a pH regulator solution to obtain a mixed solution A, controlling the pH of the mixed solution A to be 0.8-1.6, S2, mixing the mixed solution A with ammonia water to obtain a mixed material B, controlling the pH of the mixed material B to be 6-7, S3, and carrying out spray pyrolysis on the obtained mixed material B to obtain the manganese iron phosphate material. According to the preparation method provided by the application, through limiting the pH values of the mixed solution A and the mixed material B, mn element and Fe element in the raw materials can be uniformly precipitated, so that the element distribution in the obtained manganese iron phosphate material is uniform, and meanwhile, the precise regulation and control of Mn element and Fe element in the manganese iron phosphate material are realized through a spray pyrolysis technology under specific conditions.

Inventors

  • WU LIN

Assignees

  • 万华化学集团电池科技有限公司
  • 万华化学(烟台)电池产业有限公司
  • 万华化学(烟台)电池材料科技有限公司
  • 万华化学集团股份有限公司

Dates

Publication Date
20260508
Application Date
20241031

Claims (12)

  1. 1. The preparation method of the ferromanganese phosphate material is characterized by comprising the following steps: S1, mixing an iron salt solution, a manganese salt solution, a phosphoric acid solution and a pH regulator solution to obtain a mixed solution A, and controlling the pH of the mixed solution A to be 0.8-1.6; S2, mixing the mixed solution A with ammonia water to obtain a mixed material B, and controlling the pH value of the mixed material B to be 6-7; And S3, carrying out spray pyrolysis on the obtained mixed material B, wherein the temperature of spray pyrolysis treatment is 500-750 ℃, the atomization pressure is 0.3-0.8 MPa, the feeding flow is 2-60L/min, so as to obtain a ferromanganese phosphate material, and recovering the evaporated solvent.
  2. 2. The method for preparing a manganese iron phosphate material according to claim 1, wherein in step S1, anions in the iron salt solution, the manganese salt solution and the pH adjustor are the same; optionally, the anion is chloride or nitrate.
  3. 3. The method for producing a manganese iron phosphate material according to claim 2, wherein in step S3, the spray pyrolysis treatment is performed at a temperature of 550 ℃ to 650 ℃, the atomization pressure is 0.4MPa to 0.6MPa, and the feed flow is 20L/min to 30L/min.
  4. 4. The method for producing a manganese iron phosphate material according to any one of claims 1 to 3, wherein in step S1, the molar ratio of (Fe+Mn): P in terms of element in the mixed solution A is 1 (1 to 1.05) and the molar ratio of Mn: fe is x (1 to x), wherein 0.2≤x≤0.8.
  5. 5. The method for preparing a manganese iron phosphate material according to claim 4, wherein in the step S1, the total concentration of the iron salt and the manganese salt in the mixed solution a is 1mol/L to 4mol/L.
  6. 6. A ferromanganese phosphate material prepared by the preparation method of any one of claims 1 to 5, optionally having a specific surface area of 5 to 14cm 2 /g.
  7. 7. A lithium iron manganese phosphate material, characterized in that the material is prepared by using the lithium iron manganese phosphate material according to claim 6.
  8. 8. The preparation method of the lithium iron manganese phosphate material is characterized by comprising the following steps of: s11, mixing the manganese iron phosphate material, a lithium source, a carbon source, an additive and water according to claim 7 to obtain slurry A; S12, carrying out spray drying on the slurry A to obtain powder B; And S13, sintering and crushing the powder B in an inactive atmosphere to obtain the lithium iron manganese phosphate material.
  9. 9. The method for producing a lithium iron manganese phosphate material according to claim 8, wherein at least one of the following (1) to (10) is satisfied: (1) In the step S11, the molar ratio of Li (Fe+Mn) is (1-1.05) 1; (2) The mass ratio of the carbon source to the ferromanganese phosphate material is 0.05-0.2:1; (3) The mass ratio of the additive to the ferromanganese phosphate material is 0.002-0.01:1; (4) The solid content of the slurry A is 20-50wt%; (5) The lithium source comprises at least one of lithium carbonate, lithium hydroxide and lithium oxide; (6) The carbon source comprises at least one of glucose, sucrose, polyethylene glycol and starch; (7) The additive comprises at least one of titanium dioxide, magnesium oxide, zirconium oxide, yttrium oxide and vanadium pentoxide; (8) The air inlet temperature of the spray drying is 220-260 ℃ and the air outlet temperature is 105-120 ℃; (9) The sintering temperature is 600-850 ℃ and the sintering time is 4-20h; (10) In step S13, the material is pulverized to a particle diameter Dv50 of 0.6-1.5 μm.
  10. 10. A positive electrode sheet, characterized by comprising: A positive electrode current collector, and The positive electrode active material layer is arranged on at least one side of the positive electrode current collector, and comprises the lithium iron manganese phosphate material according to claim 7 or the lithium iron manganese phosphate material prepared by the preparation method according to any one of claims 8-9.
  11. 11. A secondary battery comprising the positive electrode tab of claim 12.
  12. 12. An electric device comprising the secondary battery according to claim 13.

Description

Manganese iron phosphate material and preparation method and application thereof Technical Field The application belongs to the technical field of secondary batteries, and particularly relates to a manganese iron phosphate material, a preparation method and application thereof. Background The lithium iron phosphate has been applied to electric automobiles on a large scale based on the advantages of good safety, long cycle life, low cost and the like, but the energy density of the lithium iron phosphate material itself limits the application of the lithium iron phosphate material to long-endurance mileage automobiles. The manganese ions are introduced into the ferric phosphate, so that the working voltage can be increased from 3.4V to 4.1V, the energy density can be increased by 15% -20%, and the method has the advantages of long cycle life, high thermal stability, high safety and the like, and is expected to be applied to long-endurance automobiles. In the prior art, a coprecipitation method is generally adopted to prepare a lithium iron manganese phosphate material, but the multiplying power performance of the obtained material is still required to be further improved. Disclosure of Invention The application provides a manganese iron phosphate material, a preparation method and application thereof, and aims to solve the problem that the multiplying power performance of a manganese iron phosphate lithium material needs to be further improved. In a first aspect, the application provides a method for preparing a manganese iron phosphate material, comprising the following steps: S1, mixing an iron salt solution, a manganese salt solution, a phosphoric acid solution and a pH regulator solution to obtain a mixed solution A, and controlling the pH of the mixed solution A to be 0.8-1.6; S2, mixing the mixed solution A with ammonia water to obtain a mixed material B, and controlling the pH value of the mixed material B to be 6-7; S3, carrying out spray pyrolysis on the obtained mixed material B, wherein the temperature of spray pyrolysis treatment is 500-750 ℃, the atomization pressure is 0.3-0.8 MPa, and the feeding flow is 2-60L/min, so as to obtain the ferromanganese phosphate material. In some embodiments, in step S1, the anions in the iron salt solution, manganese salt solution, pH adjuster are the same, optionally chloride or nitrate. In some embodiments, the spray pyrolysis treatment is at a temperature of 550 ℃ to 650 ℃, an atomization pressure of 0.4MPa to 0.6MPa, and a feed flow of 20L/min to 30L/min; in some embodiments, in the step S1, the mole ratio of (Fe+Mn): P in the mixed solution A is 1 (1-1.05) and the mole ratio of Mn: fe is x (1-x), wherein 0.2≤x≤0.8. In some embodiments, in step S1, the total concentration of the iron salt and the manganese salt in the mixed liquor A is 1mol/L-4mol/L. In a second aspect, the application provides a manganese iron phosphate material prepared by the preparation method. In a third aspect, the application provides a lithium iron manganese phosphate material, which is prepared from the above-mentioned lithium iron manganese phosphate material. In a fourth aspect, the application provides a preparation method of a lithium iron manganese phosphate material, comprising the following steps: S11, mixing the manganese iron phosphate material, a lithium source, a carbon source, an additive and water to obtain slurry A; S12, carrying out spray drying on the slurry A to obtain powder B; And S13, sintering and crushing the powder B in an inactive atmosphere to obtain the lithium iron manganese phosphate material. In some embodiments, the method of preparing a lithium iron manganese phosphate material satisfies at least one of the following (1) - (10): (1) In the step S11, the molar ratio of Li (Fe+Mn) is (1-1.05) 1; (2) The mass ratio of the carbon source to the ferromanganese phosphate material is 0.05-0.2:1; (3) The mass ratio of the additive to the ferromanganese phosphate material is 0.002-0.01:1; (4) The solid content of the slurry A is 20-50wt%; (5) The lithium source comprises at least one of lithium carbonate, lithium hydroxide and lithium oxide; (6) The carbon source comprises at least one of glucose, sucrose, polyethylene glycol and starch; (7) The additive comprises at least one of titanium dioxide, magnesium oxide, zirconium oxide, yttrium oxide and vanadium pentoxide; (8) The air inlet temperature of the spray drying is 220-260 ℃ and the air outlet temperature is 105-120 ℃; (9) The sintering temperature is 600-850 ℃ and the sintering time is 4-20h; (10) In step S13, the material is pulverized to a particle diameter Dv50 of 0.6-1.5 μm. In a fifth aspect, the present application provides a positive electrode sheet, comprising: A positive electrode current collector, and The positive electrode active material layer is arranged on at least one side of the positive electrode current collector, and comprises the lithium iron manganese phosphate material or the lithium