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CN-121986073-A - Positive electrode active material powder and method for manufacturing positive electrode active material

CN121986073ACN 121986073 ACN121986073 ACN 121986073ACN-121986073-A

Abstract

The invention relates to a method for reducing Na loss when preparing a positive electrode active material powder comprising particles having a substantially octahedral shape, the method comprising mixing a Li source, a precursor comprising a transition metal and a sintering flux to obtain a mixture, and heating the mixture to obtain a heated material, wherein the transition metal comprises Ni, optionally Co and optionally Mn, wherein the sintering flux is Na 2 CO 3 , and wherein the Na loss is the difference between a first Na content in the mixture and a second Na content in the heated material, the first Na content and the second Na content being measured via ICP-OES and being relative to the total amount of the transition metal.

Inventors

  • ZHU LIANG
  • WANG SHUTAO
  • Natalia Andrea Eslava Balagan

Assignees

  • 尤米科尔公司

Dates

Publication Date
20260505
Application Date
20241010
Priority Date
20231011

Claims (15)

  1. 1. A method for reducing Na loss in a positive electrode active material powder comprising particles having a substantially octahedral shape, the method comprising: Mixing a Li source, a transition metal-containing precursor, and a sintering flux to obtain a mixture, and Heating the mixture to obtain a heated material, Wherein the transition metal comprises Ni, co and Mn, Wherein the sintering flux is Na 2 CO 3 , and Wherein the Na loss is the difference between a first Na content in the mixture and a second Na content in the heated material, the first Na content and the second Na content being measured via ICP-OES and being relative to the total amount of the transition metal.
  2. 2. The method according to claim 1, wherein the Na loss is less than 10.0at%, preferably less than 8.0at%, more preferably less than 6.0at%, most preferably less than 4.0at%, relative to the total amount of transition metals.
  3. 3. The method according to claim 1 or 2, wherein the step of heating the mixture is performed at 700 to 1000 ℃, preferably 750 to 950 ℃, more preferably 800 to 920 ℃.
  4. 4. The method according to any one of the preceding claims, wherein the step of heating the mixture is performed for 2 to 15 hours, preferably 3.5 to 13.5 hours, more preferably 4 to 12 hours.
  5. 5. The method of any one of the preceding claims, wherein the transition metal comprises: Ni with the content of x, wherein x is more than or equal to 35.0at% and less than or equal to 98.0at% relative to the total amount of the transition metal; mn in an amount of y, wherein 0.0at% < y≤40.0at% relative to the total amount of the transition metal; co in an amount of z, wherein 0.0at% < z≤20.0at%, relative to the total amount of the transition metal, and D having a content of a, wherein 0.0at% a≤5.0at% relative to the total amount of the transition metal, Wherein D is at least one element selected from the group consisting of Al, B, ba, ca, cr, fe, mg, mo, na, nb, S, si, sr, ti, V, W, Y, zn and Zr, Wherein x+y+z+a is 100.0at%, and Wherein the Ni, mn, co and D contents are measured via ICP-OES.
  6. 6. The method of claim 5, wherein 50.0at% x≤95.0 at%, preferably 60.0at% x≤90.0 at%, more preferably 70.0at% x≤88.0 at%, relative to the total amount of the transition metal.
  7. 7. The method according to claim 5 or 6, wherein 0.0at% < y+.10.0 at%, preferably 1.0at% +.y+.9.0 at%, more preferably 2.0at% +.y+.8.0 at%, relative to the total amount of transition metal.
  8. 8. The method according to any one of claims 5 to 7, wherein 0.0at% < z +.10.0 at%, preferably 1.0at% +.z +.9.0 at%, more preferably 2.0at% +.z +.8.0 at%, relative to the total amount of the transition metal.
  9. 9. The method according to any one of claims 5 to 8, wherein 0.0at% a% 3.0at%, preferably 0.0at% a% 2.0at%, more preferably 0.0at% a% 1.0at% relative to the total amount of the transition metal.
  10. 10. The method of any one of the preceding claims, wherein the Li source is LiOH.
  11. 11. The method of any one of the preceding claims, wherein the step of heating the mixture is performed in a furnace or kiln.
  12. 12. The method of any of the preceding claims, the method further comprising: Mixing the heated material with an aqueous solution to obtain a slurry; filtering the slurry to obtain a filtered material, and Drying the filtered material.
  13. 13. The method according to claim 12, wherein the step of mixing the heated material is performed for 3 to 20 minutes, preferably 5 to 15 minutes.
  14. 14. The method of claim 12 or 13, wherein the step of drying the filtered material is performed at a temperature between 60 ℃ and 100 ℃ for 1 to 20 hours.
  15. 15. The method of any one of claims 12 to 14, wherein the step of drying the filtered material is performed by vacuum filtration.

Description

Positive electrode active material powder and method for manufacturing positive electrode active material Technical Field The present invention relates to a method for reducing Na loss in a positive electrode active material powder comprising particles having a substantially octahedral shape. Background The positive electrode active material powder composed of primary particles having a substantially octahedral shape morphology can reduce the internal resistance of the battery and enhance the repetitive cycle characteristics of the battery. Kimijima et al, crystal Growth AND DESIGN, 2016, 16, pages 2618-2623 ("Kimijima") describe that when a mixture of a sintering flux comprising nickel (Ni), manganese (Mn) and cobalt (Co) precursors, lithium hydroxide (LiOH H 2 O) and sodium (Na) is heated, na + ions in the sintering flux promote the formation of particles having an octahedral shape. Sintering fluxes are liquid phase agents that separate the primary particles of the agglomerates and accelerate the individual growth of each primary particle. Kimijima discloses a combination of lithium sulfate (Li 2SO4) and sodium carbonate (Na 2CO3) or sodium sulfate (Na 2SO4) as sintering flux. Kim et al APPLIED MATERIALS AND INTERFACES, 2012, 4, pages 2329-2333 ("Kim") disclose that particles grow in the shape of octahedra when sodium chloride (NaCl) is used as sintering flux. However, when a mixture containing a lithium (Li) source, a precursor, and a sintering flux is heated, the sintering flux may evaporate from the mixture. Na in the evaporated sintered flux may deposit on the walls of the furnace or kiln and then cause corrosion and contamination of the furnace or kiln. Therefore, when preparing a positive electrode active material powder containing octahedral shape particles, it is necessary to reduce Na loss in a mixture containing a Li source, a precursor, and a Na-containing sintering flux. A first object of the present invention is to provide a method for reducing Na loss when preparing a positive electrode active material powder comprising particles having a substantially octahedral shape. A second object of the present invention is to provide a positive electrode active material powder obtainable by the method according to the present invention. A third object of the present invention is to provide a battery comprising the positive electrode active material powder according to the present invention. A fourth object of the present invention is to provide the use of Na 2CO3 for reducing Na loss in the preparation of the positive electrode active material powder according to the present invention. Disclosure of Invention The first object is achieved by providing a method comprising: Mixing a Li source, a transition metal-containing precursor, and a sintering flux to obtain a mixture, and The mixture is heated to obtain a heated material, Wherein the transition metal comprises Ni, optionally Co and optionally Mn, Wherein the sintering flux is Na 2CO3, and Wherein the Na loss is the difference between a first Na content in the mixture and a second Na content in the heated material, the first Na content and the second Na content being measured via ICP-OES and being relative to the total amount of transition metal. The inventors have surprisingly found that when Na 2CO3 is used as sintering flux to prepare a positive electrode active material powder comprising particles having a substantially octahedral shape, the Na loss in the mixture during heating of the mixture is reduced. The second object is achieved by providing a positive electrode active material powder obtainable by the method according to the present invention. The third object is achieved by providing a battery comprising the positive electrode active material powder according to the present invention. The fourth object is achieved by providing a use of Na 2CO3 for reducing Na loss in preparing the positive electrode active material powder according to the present invention. Drawings Fig. 1a is an SEM image of EX 3. Fig. 1b is a post-treatment SEM image of EX3 to calculate the proportion of particles having a substantially octahedral shape. Fig. 2a to 2c are SEM images of EX2 to calculate the proportion of particles having a substantially octahedral shape. Fig. 3a and 3b are SEM images of EX3 to calculate the proportion of particles having a substantially octahedral shape. Fig. 4a and 4c are SEM images of CEX1 to calculate the proportion of particles having a substantially octahedral shape. Fig. 5a and 5c are SEM images of CEX2 to calculate the proportion of particles having a substantially octahedral shape. Detailed Description In the following detailed description, preferred embodiments are described in detail to enable practice of the invention. While the invention has been described with reference to these specific preferred embodiments, it is to be understood that the invention is not limited to these preferred embodiments. On the contrary, the inve