Ternary single crystal positive electrode material, preparation method therefor and use thereof

Patent metadata

Field	Value
Publication number	US-11888145-B2
Application number	US-202118245886-A
Country	US
Kind code	B2
Filing date	Aug 3, 2021
Priority date	Sep 24, 2020
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

Disclosed are a ternary single crystal positive electrode material, a preparation method therefor and use thereof. The preparation method comprises the following steps: mixing a ternary polycrystalline micropowder, raising a temperature, carrying out a primary sintering, and lowering the temperature to obtain an intermediate; subjecting the intermediate to jet pulverization to obtain a single crystal material, washing the single crystal material with water, and centrifugally drying the single crystal material to obtain a material with a residual alkali content of less than 1500 ppm; and adding a coating agent to the material, raising a temperature, carrying out a secondary sintering, and lowering the temperature to obtain the ternary single crystal positive electrode material. In the present disclosure, by using a jet pulverization device to open a polycrystalline material to form small single crystal particles, the electrochemical performance and the energy density of the material is improved.

First claim

The invention claimed is:

1. A method for preparing a ternary single crystal positive electrode material, comprising the following steps:
(1) mixing a ternary polycrystalline micropowder, raising a temperature, carrying out a primary sintering, and lowering the temperature to obtain an intermediate;
(2) subjecting the intermediate to jet pulverization to obtain a single crystal material, washing the single crystal material with water, and centrifugally drying the single crystal material to obtain a material with a residual alkali content of less than 1500 ppm; and
(3) adding a coating agent to the material, raising a temperature, carrying out a secondary sintering, and lowering the temperature to obtain the ternary single crystal positive electrode material; wherein the coating agent is at least one of an oxide, hydroxide and salt of a metal, or an oxide and fluoride of a non-metal, or a corresponding acid and salt of the non-metal; the metal is at least one of Al, Ce, Y, Zn, Si, Cr, Nb, Mg, La, Sr, Zr, Sn, Na, Ca, Sb, V, and W; and the non-metal is at least one of B, P, F, C, and S, with aluminum hydroxide being excluded;
wherein in step (1), the ternary polycrystalline micropowder is an unqualified product produced by means of mechanical grinding of the ternary polycrystalline material during crushing, which is a by-product produced during crushing of the ternary polycrystalline material; and a chemical formula of the ternary polycrystalline micropowder is LiNi x Co y Mn z O 2 , with 0.5≤x≤0.95, 0≤y≤0.4, 0.05≤z≤0.4, and x+y+z=1.

2. The method according to claim 1 , wherein in step (1), a temperature of the primary sintering is 600-900° C., and the primary sintering lasts for is 4-30 h.

3. The method according to claim 1 , wherein in step (1), an atmosphere in which the primary sintering is carried out is one of air or oxygen; and a gas introduction rate during the primary sintering is 5-15 m 3 /h.

4. The method according to claim 1 , wherein in step (2), requirements for the particle size of the single crystal material are: a D v 50 of 2.0-4.0 μm and a D v 99 of less than 10 μm.

5. The method according to claim 1 , wherein in step (2), a mass ratio of the water to the single crystal material during the washing with water is (0.5-3.0): 1; a speed of the washing with water is 150-450 rpm; and the washing with water lasts for 1-30 mm.

6. The method according to claim 1 , wherein in step (3), a temperature of the secondary sintering is 200-400° C., and the secondary sintering lasts for 4-20 h; and an atmosphere in which the secondary sintering is carried out is one of air or oxygen.

7. A ternary single crystal positive electrode material, wherein the ternary single crystal positive electrode material is prepared by the method of claim 1 , a chemical formula of the ternary single crystal positive electrode material is LiNi x Co y Mn z O 2 @M, wherein the coating agent is at least one of an oxide and fluoride of a non-metal, or a corresponding acid and salt of the non-metal, wherein M is at least one of Si, B, P, F, C, S; and Sb, with 0.5≤x≤0.95, 0≤y≤0.4, 0.05≤z≤0.4, and x+y+z=1; a resistivity of the ternary single crystal positive electrode material is 450-650 Ω·cm, a first discharge specific capacity is 200-206 mAh/g, a capacity retention rate after 50 cycles is greater than 96%, and a compaction density is 3.3-3.5 g/cm 3 .

8. A lithium ion battery, comprising the ternary single crystal positive electrode material of claim 7 .

Assignees

• Guangdong Brunp Recycling Technology Co Ltd
• Hunan Brunp Recycling Tech Co Ltd
• Hunan Brunp Vehicles Recycling Co Ltd

Inventors

• Li Feilong
• Ruan Dingshan
• Han Shuai
• Ma Wenzhu
• Wang Quele
• Fang Qingcheng
• Li Changdong

Classifications

• H01M4/50

  of manganese · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/0471 Primary

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title