Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing same, and nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10388953-B2
Application number	US-201515531656-A
Country	US
Kind code	B2
Filing date	Nov 27, 2015
Priority date	Nov 28, 2014
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

Provided are a lithium-manganese-nickel composite oxide carrying an organic phosphate with a high capacity and a high cycle characteristic when used as a positive electrode active material of a secondary battery, a method for producing the same, and also a nonaqueous electrolyte secondary battery using the lithium-manganese-nickel composite oxide as a positive electrode active material. The positive electrode active material for a nonaqueous electrolyte secondary battery, wherein an organic phosphite compound or an organic phosphate compound having an organic functional group composed of an alkyl group, an aryl group, and the like adheres to a part or the entire of a particle surface of the lithium-manganese-nickel composite oxide represented by general formula: LitMn2-x-yNixMyO4 (wherein 0.96<t≤1.25, 0.40≤x≤0.60, 0≤y≤0.20, and M represents at least one element selected from Mg, Al, Si, Ti, Cr, Fe, Co, Cu and Zn).

First claim

The invention claimed is:

1. A positive electrode active material for a nonaqueous electrolyte secondary battery, wherein one or both of an organic phosphite compound represented by the following chemical formula (1) and an organic phosphate compound represented by the following chemical formula (2) adhere(s) to a part or an entire of a particle surface of a lithium-manganese-nickel composite oxide represented by general formula: Li t Mn 2-x-y Ni x M y O 4 (wherein 0.96<t≤1.25, 0.40≤x≤0.60, 0≤y≤0.20, and M represents at least one element selected from Mg, Al, Si, Ti, Cr, Fe, Co, Cu and Zn).

2. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein, when the organic phosphite compound or the organic phosphate compound adheres to a surface of the positive electrode active material, a part or an entire of the organic phosphite compound or the organic phosphate compound chemically changed after adhesion of the organic phosphite compound or the organic phosphate compound is chemically bound to a component of the positive electrode active material in a form of a phosphate diester compound represented by the following chemical formula (3) or a phosphonate monoester compound represented by the following chemical formula (4).

3. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein the organic phosphite compound is at least one compound selected from trimethyl phosphite and triethyl phosphite.

4. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein the organic phosphate compound is trimethyl phosphate.

5. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein an amount of phosphorus contained in the positive electrode active material is 0.10% by weight or less.

6. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein the adhesion to the surface of the positive electrode active material is based on chemical adsorption.

7. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein any one or more of a phosphate or polyphosphate compound represented by the following chemical formula (5), and a cyclic phosphate compound where both ends of a polyphosphate compound are bound to each other adheres to a part or the entire of the particle surface of the lithium-manganese-nickel composite oxide.

8. A method for producing the positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , the method comprising
contacting a lithium-manganese-nickel composite oxide particle with an atmosphere gas including one or both of a volatile organic phosphite compound and a volatile organic phosphate compound, to allow one or both of the organic phosphite compound and the organic phosphate compound to adhere to a part or an entire of a surface of the lithium-manganese-nickel composite oxide particle.

9. The method for producing the positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 8 , wherein the atmosphere gas is an inert gas.

10. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 8 , the method comprising further heating the positive electrode active material, at 100° C. to 700° C. in an oxidation atmosphere or a vacuum atmosphere.

11. A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a separator and a nonaqueous electrolyte, wherein
a positive electrode active material of the positive electrode is the positive electrode active material for a nonaqueous electrolyte secondary battery according to any one of claim 1 .

12. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the organic phosphite compound is at least one compound selected from trimethyl phosphite or triethyl phosphite.

13. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the organic phosphate compound is trimethyl phosphate.

14. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein an amount of phosphorus contained in the positive electrode active material is 0.10% by weight or less.

15. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the adhesion to the surface of the positive electrode active material is based on chemical adsorption.

16. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein any one or more of a phosphate or polyphosphate compound represented by the following chemical formula (5), and a cyclic phosphate compound where both ends of a

polyphosphate compound are bound to each other adheres to a part or the entire of the particle surface of the lithium-manganese-nickel composite oxide.

Assignees

• Sumitomo Metal Mining Co
• Sumitomo Metal Minig Co Ltd

Inventors

• Okamoto Ryosuke
• Okubo Kazuhiko

Classifications

• C01B25/40

  Polyphosphates · CPC title

• C01G53/00

  Compounds of nickel · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/36

  Selection of substances as active materials, active masses, active liquids · CPC title

• H01M4/505

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