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CN-117401725-B - Positive electrode material precursor, preparation method thereof, positive electrode material, lithium ion battery and lithium battery equipment

CN117401725BCN 117401725 BCN117401725 BCN 117401725BCN-117401725-B

Abstract

The application provides a positive electrode material precursor and a preparation method thereof, a positive electrode material, a lithium ion battery and lithium battery equipment, wherein the positive electrode material precursor comprises a plurality of secondary particles, the plurality of secondary particles comprise first type particles and second type particles, and the particle size of the first type particles is smaller than that of the second type particles; wherein the number of particles of the first type is greater than the number of particles of the second type, and the volume of particles of the first type is less than the volume of particles of the second type. The positive electrode material precursor provided by the embodiment of the application has the characteristics of more large particle volume and more small particle quantity, can give consideration to specific capacity and cycle performance, and has better application prospect.

Inventors

  • XIN WEI
  • YIN SHUO
  • WANG YIQIAO
  • TAN SHIRONG
  • CAO WEI

Assignees

  • 中伟新材料股份有限公司
  • 湖南中伟新能源科技有限公司

Dates

Publication Date
20260512
Application Date
20230920

Claims (16)

  1. 1. The positive electrode material precursor is characterized by comprising a plurality of secondary particles, wherein the plurality of secondary particles comprise first type particles and second type particles, the particle size of the first type particles is smaller than that of the second type particles, and the particle size distribution span value of the secondary particles is 0.70-1.60; Wherein the number of particles of the first type is greater than the number of particles of the second type, and the volume of particles of the first type is less than the volume of particles of the second type; The particle size of the first type particles is less than or equal to 2 mu m, the particle size of the second type particles is more than or equal to 2 mu m, the volume ratio of the second type particles is more than or equal to 60%, the second type particles also comprise A type particles and B type particles, the particle size of the A type particles is more than or equal to 2 mu m and less than 10 mu m, and the particle size of the B type particles is more than or equal to 10 mu m.
  2. 2. The positive electrode material precursor according to claim 1, wherein, The quantity of the first type particles is more than or equal to 60 percent.
  3. 3. The positive electrode material precursor according to claim 1 or 2, wherein the positive electrode material precursor satisfies at least one of the following conditions i to iv: i. the quantity of the first type particles accounts for 91% -99%, and the quantity of the second type particles accounts for 1% -9%; the quantity of the class A particles accounts for 1 to 8.99 percent; The quantity of the B-class particles accounts for 0.01% -0.1%.
  4. 4. The positive electrode material precursor according to claim 1 or 2, wherein the positive electrode material precursor satisfies at least one of the following conditions a to j: b. The average particle diameter D50 of the secondary particles is 8.4-11.0 mu m; c. The specific surface area of the secondary particles is 8-15m 2 /g; d. The tap density of the secondary particles is 1.8-2.1g/cm 3 ; e. The peak intensity ratio I 101 /I 001 of the characteristic peak of the (101) crystal face and the characteristic peak of the (001) crystal face of the secondary particle is 1.0-1.2; f. the positive electrode material precursor satisfies the following relation: y= -Ax 2 + Bx - C Wherein x is the average particle diameter D50/mu m of the secondary particles, and y is the quantity of the first type particles in percentage/%; a is selected from 0.08-0.09, B is selected from 1.7-1.9, and C is selected from 8-9; g. the secondary particles are spherical or spheroid; h. the secondary particles are composed of a plurality of primary particles, and the primary particles are spindle-shaped or sheet-shaped; i. The secondary particles consist of a plurality of primary particles, and the length-thickness ratio of the primary particles is 3-10; j. The secondary particles are composed of a plurality of primary particles, and the thickness of the primary particles is 1.0-10.0nm.
  5. 5. The positive electrode material precursor according to claim 4, wherein in condition i, the secondary particles are composed of a plurality of primary particles, and the aspect ratio of the primary particles is 6 to 7.
  6. 6. The positive electrode material precursor according to claim 4, wherein in condition f, the secondary particles are composed of a plurality of primary particles, and the thickness of the primary particles is 2.0 to 8.0nm.
  7. 7. The positive electrode material precursor according to claim 1 or 2, wherein, The chemical general formula of the positive electrode material precursor is Ni x Co y Mn z M a (OH) 2 , wherein, x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 0.5, z is more than or equal to 0 and less than or equal to 0.5, M including one or more of Al, ti, Y, zr, W, mg, ca, ce, nb, B and Zn, a is more than or equal to 0 and less than or equal to 0.05.
  8. 8. The positive electrode material precursor according to claim 7, wherein 0.8≤x <1, 0≤y≤0.2, 0≤z≤0.2, m comprising one or more of Al, ti, Y, zr, W, mg, ca, ce, nb, B and Zn, 0≤a≤0.05.
  9. 9. The positive electrode material precursor according to claim 8, wherein the positive electrode material precursor is a layered hydroxide.
  10. 10. A method for preparing the positive electrode material precursor according to any one of claims 1 to 9, comprising the steps of: mixing a precipitant and a complexing agent to prepare a first base solution, and continuously adding the precipitant, the complexing agent and a metal salt solution into the first base solution to perform a first reaction to obtain seed crystals; Mixing the seed crystal, a precipitator and a complexing agent to prepare a second base solution, and continuously adding the precipitator, the complexing agent, a metal salt solution and the seed crystal into the second base solution to perform a second reaction to obtain a reaction product; and carrying out post-treatment on the reaction product to obtain the positive electrode material precursor.
  11. 11. The method for producing a positive electrode material precursor according to claim 10, wherein the production method satisfies at least one of the following conditions (1) to (10): (1) The metal salts include soluble salts of nickel, cobalt and/or manganese; (2) During the first reaction and the second reaction, the adding flow rate of the metal salt solution is 4.0 percent/h-7.5 percent/h of the available volume of the reaction vessel; (3) The complexing agent comprises ammonia water, and the ammonia concentration in the first reaction process is 3.5-4.5g/L; (4) The ammonia concentration in the second reaction process is 4.5-5.5g/L; (5) The pH value of the first base solution is 11.50-12.00; (6) The pH value of the reaction system of the first reaction is 11.65-11.95; (7) The pH value of the second base solution is 10.40-10.90; (8) The pH value of the reaction system of the second reaction is 10.3-10.7; (9) The reaction temperature of the first reaction and the second reaction is 50-80 ℃; (10) The first reaction and the second reaction are both carried out in a stirring state, and the stirring rotating speed is 100-200r/min.
  12. 12. The method for producing a positive electrode material precursor according to claim 11, wherein the soluble salt includes at least one of nitrate, chloride and sulfate.
  13. 13. The method for producing a positive electrode material precursor according to claim 11, wherein the total concentration of metal ions of the metal salt solution is 1.0 to 2.0mol/L.
  14. 14. A positive electrode material, characterized in that it is prepared from the positive electrode material precursor according to any one of claims 1 to 9.
  15. 15. A lithium ion battery prepared from the positive electrode material of claim 14.
  16. 16. A lithium-ion battery device prepared from the lithium-ion battery of claim 15.

Description

Positive electrode material precursor, preparation method thereof, positive electrode material, lithium ion battery and lithium battery equipment Technical Field The application relates to the technical field of positive electrode materials, in particular to a positive electrode material precursor, a preparation method thereof, a positive electrode material, a lithium ion battery and lithium battery equipment. Background With the sustainable development of new energy industries, lithium ion batteries are widely focused and studied as a novel green battery. The positive electrode material is used as an important component of the lithium ion battery, and directly influences the capacity, circulation, safety performance and the like of the lithium ion battery. The ternary positive electrode material is used as a common positive electrode material of a lithium ion battery and is always a technical core. In order to ensure the performance of the battery, the ternary positive electrode material precursors and positive electrode material products in the market are gradually developed to high nickel and stable structure. As the nickel content increases, the specific capacity of the ternary cathode material gradually increases, but the cycle performance and safety performance thereof deteriorate accordingly. Disclosure of Invention The application aims to at least improve one of the technical problems existing in the prior art, and therefore, the application provides a positive electrode material precursor, a preparation method thereof, a positive electrode material, a lithium ion battery and lithium battery equipment. The embodiment of the application provides a positive electrode material precursor, which comprises a plurality of secondary particles, wherein the plurality of secondary particles comprise first type particles and second type particles, and the particle size of the first type particles is smaller than that of the second type particles; wherein the number of particles of the first type is greater than the number of particles of the second type, and the volume of particles of the first type is less than the volume of particles of the second type. The particle size of the precursor of the positive electrode material provided by the embodiment of the application is in bimodal distribution in a particle size distribution test, and the particle sizes of the first type of particles and the second type of particles are different, wherein the particle size of the first type of particles is smaller than that of the second type of particles, as shown in fig. 4, the first type of particles are the aggregation of particles with a first peak, and the second type of particles are the aggregation of particles with a second peak, and the particle size dividing line of the first peak and the second peak can be any value of 1.8 μm,1.9 μm,2.0 μm,2.1 μm,2.2 μm,2.3 μm,2.4 μm,2.5 μm,2.6 μm,2.7 μm,2.8 μm,2.9 μm and 3.0 μm. The number of the first type particles with smaller particle size is larger than the number of the second type particles with larger particle size, namely the number of the small particles is larger, so that the contact area between the positive electrode material and the electrolyte can be increased, the specific capacity can be improved, and the volume of the second type particles with larger particle size is larger than the volume of the first type particles with smaller particle size, namely the volume of the large particles is larger, so that the circulation performance can be improved properly. Therefore, the positive electrode material precursor provided by the embodiment of the application can be used for considering specific capacity and cycle performance. In some embodiments of the present application, the positive electrode material precursor has a particle size of the first type of particles of 2 μm or less, and the second type of particles has a particle size of >2 μm. In some embodiments of the present application, the positive electrode material precursor has a number of the first type particles of 60% or more and a volume of the second type particles of 60% or more; Optionally, the first type of particles are present in an amount of 91% to 99%; optionally, the number of the second type particles is 1% -9%; optionally, the second type of particles further comprise type A particles and type B particles, wherein the particle size of the type A particles is more than 2 mu m and less than 10 mu m, and the particle size of the type B particles is more than or equal to 10 mu m; optionally, the number of the class a particles is 1% -8.99%; optionally, the amount of the B-type particles is 0.01% -0.1%. In some embodiments of the application, the positive electrode material precursor satisfies at least one of the following conditions a-j: a. The particle size distribution span value of the secondary particles is 0.70-1.60; b. The average particle diameter D50 of the secondary particles is 8.4-11.0 m