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CN-121983531-A - Composite coated ternary positive electrode material and preparation method and application thereof

CN121983531ACN 121983531 ACN121983531 ACN 121983531ACN-121983531-A

Abstract

The invention relates to the technical field of lithium ion batteries, and discloses a composite coated ternary positive electrode material, a preparation method and application thereof. According to the composite coated ternary positive electrode material, antimony elements are doped in the matrix, the Sb 5+ with high price and large ionic radius can stabilize the crystal structure and reduce cation mixed discharge, cobalt and lithium elements of the first coating layer can form a stable spinel structure on the surface of the matrix to inhibit interface side reactions, tungsten elements, aluminum elements, titanium elements and zirconium elements are coated on the surface to inhibit interface side reactions, the structural stability of the positive electrode material is improved, and the cycle stability and the thermal stability of a lithium ion battery are further improved.

Inventors

  • XU KAIHUA
  • SUN HAO
  • CHEN YUJUN
  • MA YONGSONG
  • ZHANG MINGLONG
  • LIU KAIXI
  • LIU CHENFAN

Assignees

  • 格林美（无锡）能源材料有限公司

Dates

Publication Date
20260505
Application Date
20251210

Claims (10)

  1. 1. The composite coated ternary positive electrode material comprises a base material and a coating layer coated on the outer surface of the base material, and is characterized in that the coating layer comprises a first coating layer and a second coating layer, wherein the first coating layer is at least coated on part of the surface of the base material, and the second coating layer is at least coated on part of the surface of the first coating layer; The matrix material comprises antimony element; The first coating layer contains cobalt element and lithium element, and the second coating layer contains tungsten element, aluminum element, titanium element and zirconium element.
  2. 2. The composite coated ternary cathode material according to claim 1, wherein the content of cobalt element in the first coating layer is 0.1% -1.6% based on the mass of the matrix material; And/or, the content of lithium element in the first coating layer is 0.1% -1.6% based on the mass of the matrix material.
  3. 3. The composite coated ternary cathode material according to claim 1, wherein the content of tungsten element in the second coating layer is 0.1% -0.6% based on the mass of the matrix material; And/or, the content of aluminum element in the second coating layer is 0.1% -0.6% based on the mass of the matrix material; and/or, the content of titanium element in the second coating layer is 0.1% -0.6% based on the mass of the matrix material; and/or, the content of the zirconium element in the second coating layer is 0.1% -0.6% based on the mass of the matrix material.
  4. 4. The composite coated ternary positive electrode material of claim 1, wherein the chemical formula of the matrix material is Li f (Ni a Co b Mn c Sb d M e )O 2 , wherein 0.58-0.8,0.1-b-0.2,0.0003-d-0.007,0.0002-e-0.009, a+b+c+d+e= 1,1.02-f-1.08, and m is at least one of zirconium, yttrium, tungsten, and niobium.
  5. 5. A method for preparing the composite coated ternary cathode material according to any one of claims 1 to 4, comprising the steps of: (1) Mixing a nickel cobalt manganese precursor, a first lithium source and an antimony source, and then performing first sintering to obtain a matrix material; (2) Mixing the matrix material, a cobalt source and a second lithium source, and then performing second sintering to obtain a cobalt-lithium coated matrix material; (3) And mixing the cobalt-lithium coated matrix material, a tungsten source, an aluminum source, a titanium source and a zirconium source, and then performing third sintering to prepare the composite coated ternary anode material.
  6. 6. The method of preparing a composite coated ternary cathode material according to claim 5, wherein in step (1), a dopant is added, wherein the dopant comprises at least one of oxides of zirconium, yttrium, tungsten, and niobium; Optionally, the molar ratio of the total number of moles of metal elements in the matrix material to the metal elements in the dopant is 1:0.0002-0.009; And/or the molar ratio of the total number of moles of metal elements in the matrix material to the mole ratio of antimony elements in the antimony source is 1:0.0003-0.007; And/or the molar ratio of the total mole number of the metal elements in the matrix material to the mole number of the lithium elements in the first lithium source is 1:1.02-1.08; And/or the mass of cobalt element in the cobalt source accounts for 0.1-1.6% of the mass of the matrix material; and/or the mass of lithium element in the second lithium source accounts for 0.1-1.6% of the mass of the matrix material; And/or the mass of tungsten element in the tungsten source accounts for 0.1-0.6% of the mass of the matrix material; And/or, the mass of aluminum element in the aluminum source accounts for 0.1-0.6% of the mass of the matrix material; and/or, the mass of titanium element in the titanium source accounts for 0.1-0.6% of the mass of the matrix material; And/or, the mass of the zirconium element in the zirconium source accounts for 0.1-0.6% of the mass of the matrix material.
  7. 7. The method for preparing the composite coated ternary cathode material according to claim 5 or 6, wherein the chemical formula of the nickel-cobalt-manganese precursor is Ni x Co y Mn z (OH) 2 , x is more than or equal to 0.6 and less than or equal to 0.8,0.1, y is more than or equal to 0.2, and x+y+z=1.
  8. 8. The method for preparing a composite coated ternary cathode material according to claim 5 or 6, wherein the first lithium source comprises at least one of lithium hydroxide and lithium carbonate; and/or, the antimony source comprises antimony oxide; And/or the cobalt source comprises at least one of cobalt hydroxide, cobalt oxyhydroxide and tricobalt tetraoxide; And/or, the second lithium source comprises lithium hydroxide; and/or the tungsten source comprises at least one of tungsten oxide, tungstic acid, ammonium paratungstate; And/or, the aluminum source comprises at least one of aluminum oxide and aluminum hydroxide; and/or, the titanium source comprises at least one of titanium oxide and titanium hydroxide; and/or the zirconium source comprises at least one of zirconia, zirconium hydride, zirconium iodide.
  9. 9. The method for preparing the composite coated ternary cathode material according to claim 5, wherein the temperature of the first sintering is 700-1000 ℃, the time is 8-15 h, the heating rate is 1-5 ℃ per minute, and the sintering atmosphere is oxygen or air; And/or the temperature of the second sintering is 600-900 ℃, the time is 3-7 h, the temperature rising rate is 1.5-5 ℃ per minute, and the sintering atmosphere is oxygen or air; And/or the temperature of the third sintering is 300-500 ℃, the time is 3-7 h, the temperature rising rate is 1.5-5 ℃ per minute, and the sintering atmosphere is oxygen or air.
  10. 10. A composite coated ternary cathode material according to any one of claims 1 to 4 or a composite coated ternary cathode material prepared by a preparation method according to any one of claims 5 to 9 and application thereof in lithium ion batteries.

Description

Composite coated ternary positive electrode material and preparation method and application thereof Technical Field The invention relates to the technical field of lithium ion batteries, in particular to a composite coated ternary positive electrode material, a preparation method and application thereof. Background With the gradual expansion of application of the lithium ion battery in the field of new energy automobiles, the endurance mileage becomes a key factor for restricting the development of the new energy automobiles, and the improvement of the energy density of the lithium ion battery is an effective way for solving endurance anxiety. The high-voltage line enables the anode material to remove more lithium ions under higher voltage by increasing the battery charging cut-off voltage, thereby simultaneously increasing the capacity and the working voltage and further achieving the purpose of increasing the energy density. Meanwhile, the nickel content of the high-voltage material is relatively low, and the production process is less complex than that of high-nickel ternary, so that the high-voltage positive electrode material has certain safety improvement while improving the energy density. However, in a high voltage (> 4.4V) environment, with the massive release of lithium ions, the ternary cathode material may suffer from problems of reduced crystal structure stability, disordered ion arrangement, irreversible phase change and the like, resulting in poor results of shortened cycle life, reduced thermal stability and the like of the battery. In the prior art, methods such as metal ion doping, artificial protection layer establishment, high-voltage electrolyte and additive matching are often adopted for alleviation, but the circulation stability is still poor. Therefore, how to optimize and adjust the ternary positive electrode material and the preparation method thereof to prepare the ternary positive electrode material with stable structure so as to improve the cycle life and the thermal stability of the lithium ion battery is a technical problem to be solved in the field. Disclosure of Invention The invention provides a composite coated ternary positive electrode material, which solves the problems of short cycle life and poor thermal stability of a lithium ion battery in the prior art. The invention also provides a preparation method of the composite coated ternary positive electrode material. In a first aspect, the invention provides a composite coated ternary positive electrode material, which comprises a matrix material and a coating layer coated on the outer surface of the matrix material, wherein the coating layer comprises a first coating layer and a second coating layer, the first coating layer is coated on at least part of the surface of the matrix material, and the second coating layer is coated on at least part of the surface of the first coating layer; The matrix material comprises antimony element; The first coating layer contains cobalt element and lithium element, and the second coating layer contains tungsten element, aluminum element, titanium element and zirconium element. In some alternative embodiments, the content of cobalt element in the first coating layer is 0.1% -1.6% by mass of the matrix material. In some alternative embodiments, the content of the lithium element in the first coating layer is 0.1% -1.6% by mass of the matrix material. In some alternative embodiments, the tungsten element content in the second cladding layer is 0.1% -0.6% by mass of the matrix material. In some alternative embodiments, the aluminum element content in the second cladding layer is 0.1% -0.6% by mass of the matrix material. In some alternative embodiments, the titanium element in the second coating layer is present in an amount of 0.1% to 0.6% by mass of the matrix material. In some alternative embodiments, the content of elemental zirconium in the second cladding layer is from 0.1% to 0.6% by mass of the matrix material. In some alternative embodiments, the matrix material has the chemical formula Li f(NiaCobMncSbdMe)O2, where 0.58 A≤ 0.8,0.1 B≤ 0.2,0.0003 D≤ 0.007,0.0002 E≤0.009, a+b+c+d+e= 1,1.02≤f≤1.08, and M is at least one of zirconium, yttrium, tungsten, niobium. In a second aspect, the invention provides a preparation method of the composite coated ternary cathode material in the first aspect, which comprises the following steps: (1) Mixing a nickel cobalt manganese precursor, a first lithium source and an antimony source, and then performing first sintering to obtain a matrix material; (2) Mixing the matrix material, a cobalt source and a second lithium source, and then performing second sintering to obtain a cobalt-lithium coated matrix material; (3) And mixing the cobalt-lithium coated matrix material, a tungsten source, an aluminum source, a titanium source and a zirconium source, and then performing third sintering to prepare the composite coated ternary anode material. In some