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CN-122025622-A - Lithium ion battery anode material and preparation method and application thereof

CN122025622ACN 122025622 ACN122025622 ACN 122025622ACN-122025622-A

Abstract

The invention relates to the technical field of lithium ion battery materials, in particular to a lithium ion battery positive electrode material which meets the following relational expression that P= (K is 10 2 ）+[（C-100）*10 2 /L ]. Times.2, wherein P is the structural stress coefficient of the positive electrode material, P is more than or equal to 2.51 and less than or equal to 12.00, K is the porosity of the positive electrode material, K is more than or equal to 1% and less than or equal to 10%, C is the grain size of the positive electrode material, C is more than or equal to 100nm and less than or equal to 400nm, L is the granularity D 50 of the positive electrode material, L is more than or equal to 8 mu m and less than or equal to 16 mu m, and a preparation method of the lithium ion battery positive electrode material is provided.

Inventors

  • She Jiaxin
  • LUO GUI
  • TANG BO
  • ZHOU HUI
  • XIA XIN

Assignees

  • 巴斯夫杉杉电池材料有限公司

Dates

Publication Date
20260512
Application Date
20241111

Claims (10)

  1. 1. A positive electrode material for a lithium ion battery, wherein the positive electrode material satisfies the following relationship: P=(K*10 2 ）+[（C-100）*10 2 /L]^2; wherein P is the structural stress coefficient of the positive electrode material, and P is more than or equal to 2.51 and less than or equal to 12.00; k is the porosity of the positive electrode material, and K is more than or equal to 1% and less than or equal to 10%; C is the grain size of the positive electrode material, C is more than or equal to 100nm and less than or equal to 400nm; L is the granularity D 50 of the positive electrode material, and L is more than or equal to 8 mu m and less than or equal to 16 mu m.
  2. 2. The positive electrode material of the lithium ion battery according to claim 1, wherein the positive electrode material matrix is coated with B element, the chemical formula of the positive electrode material matrix is Li a Ni 1-x-y-z Co x M y N z O 2 , wherein M is Mn or Al, N is at least one of Zr, al, ti, mg, Y, W, mo, sr, ba, la, ca, si, nb, ta, ce, ga, sn and Sb, a is more than or equal to 0.90 and less than or equal to 1.20,0, x is more than or equal to 0.30,0, y is more than or equal to 0.30,0 and less than or equal to 0.05, and x+y+z is more than or equal to 0.30.
  3. 3. The positive electrode material for a lithium ion battery according to claim 2, further comprising an S element, wherein the S element accounts for 0.01% -0.30% of the total mass of the positive electrode material.
  4. 4. A method for preparing a positive electrode material for a lithium ion battery according to any one of claims 1 to 3, comprising the steps of: mixing a positive electrode material precursor, a pore-forming agent and a doping agent at a high speed, heating to a first sintering temperature, performing primary heat preservation sintering, cooling to the heat preservation temperature, performing heat preservation sintering, and naturally cooling to room temperature to obtain a primary sintering intermediate; washing and drying the primary sintering intermediate to obtain a dried intermediate; and mixing the dry intermediate with a coating agent to obtain a mixed material, heating to a second sintering temperature, performing secondary heat preservation and sintering, and naturally cooling to room temperature to obtain the lithium ion anode material.
  5. 5. The method according to claim 4, wherein the pore-forming agent is a sulfate or sulfate hydrate containing Zr, al, ti, mg, Y, W, mo, sr, ba, la, ca, si, nb, ta, ce, ga, sn and Sb, the molar ratio of sulfate to the matrix in the pore-forming agent is 0.01-0.05, the dopant is an oxide, hydroxide or carbonate containing at least one element of Zr, al, ti, mg, Y, W, mo, sr, ba, la, ca, si, nb, ta, ce, ga, sn and Sb, and the molar ratio of metal element to the matrix in the dopant is 0-0.1.
  6. 6. The method of claim 4, wherein the first sintering temperature is raised to 600-900 ℃ at a temperature rate of 1-5 ℃ per minute in the air or oxygen atmosphere in one-time heat-preserving sintering, the heat-preserving sintering is performed for 8-20 hours, and the temperature is lowered to 300-450 ℃ at a temperature-lowering rate of 0.5-2.5 ℃ per minute, and the heat-preserving sintering is performed for 3-8 hours.
  7. 7. The method for preparing the porous ceramic material according to claim 4, wherein in the process of washing and drying the primary sintering intermediate, deionized water is adopted to wash the primary sintering intermediate for 1-15 min according to the mass-to-solid-to-liquid ratio of 1.0-3.0, the water content is reduced to 10% by suction filtration for 10-30 min, and then the primary sintering intermediate is dried in a vacuum drying oven for 5-20 h, so that a dried intermediate is obtained.
  8. 8. The method according to claim 4, wherein the coating agent is at least one of boric acid and boron oxide, and the element B accounts for 0.01% -0.30% of the total mass of the dry intermediate.
  9. 9. The method of claim 4, wherein in the secondary heat-preserving sintering, the temperature is raised to 250-350 ℃ at a second temperature-raising rate of 1-5 ℃ per minute under the atmosphere of oxygen or air, the temperature is preserved and sintered for 4-12 hours, and then the lithium ion positive electrode material is obtained by sieving the lithium ion positive electrode material with a 300-mesh sieve after naturally cooling to room temperature.
  10. 10. Use of a lithium ion battery positive electrode material according to any one of claims 1-3 in a lithium ion battery.

Description

Lithium ion battery anode material and preparation method and application thereof Technical Field The invention relates to the technical field of lithium ion battery materials, in particular to a lithium ion battery anode material, a preparation method and application thereof. Background With the rapid development of the electric automobile market, the requirements on the efficiency and the safety performance of the lithium ion battery are higher and higher. The positive electrode material is used as the most important component in the lithium ion battery, and plays a vital role in the performance of the battery. Failure of lithium batteries is often closely related to the thermal stability of the material and particle breakage. The volume change in the charge-discharge process can lead to the release of stress in the material, finally causes particle breakage in the later period of circulation, aggravates the side reaction of the lithium battery, and causes potential safety hazard. Through researches, the porosity, grain size and granularity of the positive electrode material are closely related to internal stress, and the granularity and grain size of the current positive electrode material are usually adjusted through precursor design and sintering temperature, but the porosity of the material is difficult to effectively adjust. The common method is to adjust the porosity by adjusting the manufacturing process of the precursor, but factors influencing the porosity in the precursor preparation process are more, the stability of the process is difficult to maintain in the adjustment process, and the size and the distribution of the porosity in the material cannot be reliably adjusted. The patent document with the publication number of CN117317209A discloses a positive electrode material and a preparation method thereof, and aims to solve the problems that the porosity of the existing positive electrode material is difficult to regulate and control and the reproducibility is poor. However, the positive electrode material only takes into consideration the battery capacity and cycle performance, and does not take into consideration the thermal stability of the material, so that the safety performance of the positive electrode material cannot be ensured. Disclosure of Invention The invention aims to solve the technical problems and overcome the defects in the background art, and provides a lithium ion battery anode material with high battery capacity, excellent cycle performance, good thermal stability and structural stability, and a preparation method and application thereof. In order to solve the technical problems, the technical scheme provided by the invention is that the positive electrode material of the lithium ion battery meets the following relational expression that P= (K is 10 2）+[（C-100）*102/L ]. Times.2; wherein P is the structural stress coefficient of the positive electrode material, and P is more than or equal to 2.51 and less than or equal to 12.00; k is the porosity of the positive electrode material, and K is more than or equal to 1% and less than or equal to 10%; C is the grain size of the positive electrode material, C is more than or equal to 100nm and less than or equal to 400nm; L is the granularity D 50 of the positive electrode material, and L is more than or equal to 8 mu m and less than or equal to 16 mu m. In one embodiment, the positive electrode material matrix is coated with B element, and the chemical general formula of the positive electrode material matrix is Li aNi1-x-y-zCoxMyNzO2, wherein M is Mn or Al, N is at least one of Zr, al, ti, mg, Y, W, mo, sr, ba, la, ca, si, nb, ta, ce, ga, sn and Sb, a is more than or equal to 0.90 and less than or equal to 1.20,0, x is more than or equal to 0.30,0 and less than or equal to y is more than or equal to 0.30,0 and less than or equal to 0.05, and x+y+z is more than or equal to 0.30. In one embodiment, the positive electrode material further contains an S element, and the S element accounts for 0.01% -0.30% of the total mass of the positive electrode material. Based on the same inventive concept, the preparation method of the lithium ion battery anode material is also provided, and comprises the following steps: mixing a positive electrode material precursor, a pore-forming agent and a doping agent at a high speed, heating to a first sintering temperature, performing primary heat preservation sintering, cooling to the heat preservation temperature, performing heat preservation sintering, and naturally cooling to room temperature to obtain a primary sintering intermediate; washing and drying the primary sintering intermediate to obtain a dried intermediate; and mixing the dry intermediate with a coating agent to obtain a mixed material, heating to a second sintering temperature, performing secondary heat preservation and sintering, and naturally cooling to room temperature to obtain the lithium ion anode material. In one embodiment, t