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CN-121974413-A - Small particle precursor for manganese-rich cathode material and preparation method

CN121974413ACN 121974413 ACN121974413 ACN 121974413ACN-121974413-A

Abstract

The invention belongs to the technical field of lithium ion battery anode materials, and provides a small particle precursor for a manganese-rich anode material and a preparation method thereof. According to the invention, the manganese-rich precursor with finer primary particles and larger specific surface area is prepared by using the non-ammonia complexing agent, so that an oxidizing atmosphere is not needed, the preparation process is simple, the process control is stable, and the mass production conversion is convenient.

Inventors

  • ZHOU ZIGUI
  • JI TONGZONG
  • ZHENG BIN
  • HUANG YAFAN
  • YANG FAN
  • WU YOUZHI
  • ZHANG LIMING
  • SHEN JIACHENG
  • XUN RUIZHI

Assignees

  • 浙江海创锂电科技有限公司

Dates

Publication Date
20260505
Application Date
20251230

Claims (10)

  1. 1. The preparation method of the small particle precursor for the manganese-rich cathode material is characterized by adopting a non-ammonia complexing agent to replace ammonia water as a complexing agent, and comprises the following steps of: (1) Preparing a mixed metal salt solution containing nickel and manganese, and adding a non-ammonia complexing agent; (2) Preparing a base solution containing the non-ammonia complexing agent, and adjusting the pH of the base solution; (3) Under inert atmosphere, introducing the mixed metal salt solution into the base solution for coprecipitation reaction; (4) And (3) performing coprecipitation reaction until reaching the end particle size, finishing the reaction, and performing aftertreatment to obtain target precursor particles.
  2. 2. The method of preparing a small particle precursor for a manganese-rich cathode material according to claim 1, wherein the non-ammine complexing agent is at least one of EDTA or an alkali metal salt thereof.
  3. 3. The method of preparing a small particle precursor for a manganese-rich cathode material according to claim 2, wherein the non-ammine complexing agent is disodium EDTA.
  4. 4. The preparation method of the small particle precursor for the manganese-rich cathode material, which is disclosed in claim 1, is characterized in that the total concentration of nickel and manganese ions in the mixed metal salt solution in the step (1) is 1.0-2.2 mol/L, the molar ratio of nickel to manganese is x:y, x is more than or equal to 0.1 and less than or equal to 0.9, y is more than or equal to 0.1 and less than or equal to 0.9, and the concentration of the non-ammonia complexing agent in the mixed metal salt solution in the step (1) is 0.5-2.0 g/L.
  5. 5. The method for preparing the small particle precursor for the manganese-rich cathode material, which is disclosed in claim 1, is characterized in that in the step (2), the temperature of a base solution is 45-65 ℃, the pH of the base solution is 11.5-11.8, the volume of the base solution is 50% -100% of the effective volume of a reaction kettle, and the concentration of a non-ammonia complexing agent in the base solution is 0.5-2.0 g/L.
  6. 6. The method for preparing the small particle precursor for the manganese-rich cathode material, which is disclosed in claim 1, is characterized in that in the step (3), a turbine of a reaction kettle stirrer is one or two of a 4-6-blade 60-90-degree straight-blade disc turbine and a 4-6-blade 30-60-degree inclined-blade opening turbine, and the number of turbine layers is 1-3.
  7. 7. The method for preparing the small particle precursor for the manganese-rich cathode material, which is disclosed in claim 1, is characterized in that the feeding flow rate of the mixed metal salt solution in the step (3) is 1% -10% of the volume of the reaction kettle per hour, and the rotating speed of the stirrer is 900-1100 rpm.
  8. 8. The method for preparing a small particle precursor for a manganese-rich cathode material according to claim 1, wherein the endpoint particle size in the step (4) is 2-6 μm.
  9. 9. The method for preparing the small particle precursor for the manganese-rich cathode material according to claim 1, wherein the particle size of the prepared small particle precursor is 2-6 μm, the particle size distribution is 0.5-1.0, the specific surface area is not less than 20m 2 /g, and the primary particle thickness is not more than 300 nm.
  10. 10. A small particle precursor for a manganese-rich cathode material prepared according to the preparation method of any one of claims 1 to 9.

Description

Small particle precursor for manganese-rich cathode material and preparation method Technical Field The invention relates to the technical field of lithium ion batteries, in particular to a small particle precursor for a manganese-rich positive electrode material and a preparation method thereof. Background In recent years, domestic electric vehicles rapidly occupy the domestic market, the market share of traditional fuel vehicles is extruded, the development route and the technical bottleneck of the current electric vehicles are in continuous voyage and rapid charging, so that nickel-rich and single-crystal ternary materials are becoming mainstream, but the safety performance of the nickel-rich ternary positive electrode material is poor, and the cost of the manganese-rich material is only about 1/3 of that of the ternary material on the premise that the difference between the capacity and the high-nickel ternary material is not great, and the manganese-rich material has better safety performance and is widely focused by researchers. The existing precursor coprecipitation technology often uses ammonia water as a complexing agent, but for a manganese-rich material, the ammonia complexing coprecipitation effect is poor, primary particles are poor in consistency, the structural performance of the positive electrode material is easy to weaken, at present, refined primary particles are designed, the specific surface area of a small particle precursor is improved to be a widely accepted research direction, similar effects can be achieved through a micro-oxidation process, but an oxidation process has certain difficulty for the manganese-rich precursor which is easy to oxidize, the oxidation degree is difficult to quantify in a controlled angle, and the product consistency is not high, so that the mass production conversion is difficult. Disclosure of Invention The invention aims to solve the technical problems and provide a novel manganese-rich cathode material small particle precursor and a preparation method thereof, the method can refine primary particles, improve the specific surface area of the small-particle manganese-rich precursor, and achieve the effect of stable control. In order to achieve the technical purpose, the invention provides the following technical scheme: The invention provides a preparation method of a small particle precursor for a manganese-rich positive electrode material, which adopts a non-ammonia complexing agent to replace ammonia water as a complexing agent and comprises the following steps of: (1) Preparing a mixed metal salt solution containing nickel and manganese, and adding a non-ammonia complexing agent into the mixed metal salt solution; (2) Preparing a base solution containing the non-ammonia complexing agent, and adjusting the pH of the base solution; (3) Feeding is started under inert atmosphere, and the mixed metal salt solution is introduced into the base solution for coprecipitation reaction; (4) And (3) performing coprecipitation reaction until reaching the end particle size, finishing the reaction, and performing aftertreatment to obtain target precursor particles. Preferably, the non-ammonia complexing agent is at least one of EDTA (ethylene diamine tetraacetic acid) or alkali metal salts thereof, and more preferably disodium EDTA (disodium ethylene diamine tetraacetate, chemical formula C 10H14N2Na2O8). Preferably, the total concentration of nickel and manganese ions in the mixed metal salt solution in the step (1) is 1.0-2.2 mol/L, and the molar ratio of divalent nickel and manganese metal ions in the mixed metal salt is x, y, x is more than or equal to 0.1 and less than or equal to 0.9, y is more than or equal to 0.1 and less than or equal to 0.9, more preferably, x is more than or equal to 0.2 and less than or equal to 0.5, and y is more than or equal to 0.5 and less than or equal to 0.8. The non-ammonia complexing agent in the step (1) is dissolved in a mixed metal salt solution, and the concentration in the mixed metal salt solution is 0.5-2.0 g/L. Preferably, the temperature of the base solution in the step (2) is 45-65 ℃, the pH of the base solution is 11.5-11.8, the volume of the base solution is 50% -100% of the effective volume of the reaction kettle, and the concentration of the non-ammonia complexing agent in the base solution is 0.5-2.0 g/L. More preferably, the pH is adjusted by sodium hydroxide. Preferably, the turbine of the reaction kettle stirrer in the step (3) is one or two of a 4-6-blade 60-90-degree straight-blade disc turbine and a 4-6-blade 30-60-degree inclined-blade opening turbine, and the number of turbine layers is 1-3. Preferably, the inert atmosphere in the step (3) is at least one of nitrogen, helium or argon. Preferably, the feeding flow rate of the mixed metal salt solution in the step (3) is 1% -10% of the volume of the reaction kettle per hour, and the rotating speed of the stirrer is 900-1100 rpm. Preferably, the end point granu