Method for manufacturing lithium-containing complex phosphate elliptical particles

Patent metadata

Field	Value
Publication number	US-11637293-B2
Application number	US-202016892582-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Jul 8, 2016
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 μm. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

First claim

What is claimed is:

1. A manufacturing method of a positive electrode active material comprising:
a step of mixing a lithium compound, a phosphorus compound, and water to form a first mixed solution;
a step of adjusting pH by adding a first aqueous solution to the first mixed solution to form a second mixed solution;
a step of mixing an iron(II) compound with the second mixed solution to form a third mixed solution; and
a step of heating the third mixed solution under a pressure higher than or equal to 0.1 MPa and lower than or equal to 2 MPa at a highest temperature higher than 150° C. and lower than or equal to 250° C. for less than 5 hours to form a fourth mixed solution,
wherein the positive electrode active material comprises a secondary particle including a plurality of primary particles,
wherein the plurality of primary particles comprises a first particle and a second particle,
wherein the first aqueous solution is ammonium aqueous solution,
wherein pH of the third mixed solution is more than or equal to 3.5 and less than or equal to 5.0,
wherein each of the first particle and the second particle is a lithium-containing complex phosphate comprising one or more of iron, nickel, manganese, and cobalt,
wherein each of the first particle and the second particle comprises a major diameter in a major axis and a minor diameter in a minor axis when observed with a microscope,
wherein the major axes of the first particle and the second particle are substantially parallel to each other,
wherein the major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm, and
wherein a median value of particle diameters of the plurality of particles obtained with use of laser diffraction and scattering method is more than or equal to 500 nm and less than or equal to 6 μm.

2. The manufacturing method of a positive electrode active material according to claim 1 ;
wherein the positive electrode active material has an olivine structure.

3. The manufacturing method of a positive electrode active material according to claim 2 ;
wherein the positive electrode active material is represented by LiFePO 4 .

4. A manufacturing method of a positive electrode active material comprising:
a step of mixing a lithium compound, a phosphorus compound, and water to form a first mixed solution;
a step of adjusting pH by adding a first aqueous solution to the first mixed solution to form a second mixed solution;
a step of mixing an iron(II) compound with the second mixed solution to form a third mixed solution; and
a step of heating the third mixed solution under a pressure higher than or equal to 0.1 MPa and lower than or equal to 2 MPa at a highest temperature higher than 150° C. and lower than or equal to 250° C. for less than 5 hours to form a fourth mixed solution,
wherein the positive electrode active material comprises a secondary particle including a plurality of primary particles,
wherein the plurality of primary particles comprises a first particle and a second particle,
wherein the first aqueous solution is ammonium aqueous solution,
wherein pH of the third mixed solution is more than or equal to 3.5 and less than or equal to 5.0,
wherein each of the first particle and the second particle is a lithium-containing complex phosphate comprising one or more of iron, nickel, manganese, and cobalt,
wherein each of the first particle and the second particle comprises a major diameter in a major axis and a minor diameter in a minor axis when observed with a microscope,
wherein the major axes of the first particle and the second particle are substantially parallel to each other,
wherein the major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm, and
wherein a median value of particle diameters of the plurality of particles obtained with use of laser diffraction and scattering method is more than or equal to 500 nm and less than or equal to 6 μm, and
wherein a specific surface area is more than or equal to 18 m 2 /g and less than or equal to 50 m 2 /g.

5. The manufacturing method of a positive electrode active material according to claim 4 ;
wherein the positive electrode active material has an olivine structure.

6. The manufacturing method of a positive electrode active material according to claim 5 ;
wherein the positive electrode active material is represented by LiFePO 4 .

Assignees

• Semiconductor Energy Lab

Inventors

• Yoneda Yumiko
• Miwa Takuya

Classifications

• H01M2010/4278

  Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2220/10

  Batteries in stationary systems, e.g. emergency power source in plant · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title