Positive electrode active substance for non-aqueous electrolyte secondary battery and method for producing same, positive electrode mixture paste for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2020251732-A1
Application number	US-201816617768-A
Country	US
Kind code	A1
Filing date	May 31, 2018
Priority date	May 31, 2017
Publication date	Aug 6, 2020
Grant date	—

Abstract

The positive electrode active material for a nonaqueous electrolyte secondary battery contains a lithium-nickel composite oxide represented by a general formula: LiaNi1−x−yCoxMyO2+α (where 0.01≤x≤0.35, 0≤y≤0.10, 0.95≤a≤1.10, and 0≤α≤0.2; and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al) and a boron compound. At least part of the boron compound is present on the surface of the lithium-nickel composite oxide in the form of Li3BO3 and LiBO2, and a mass ratio (Li3BO3/LiBO2) between Li3BO3 and LiBO2 is at least 0.005 and up to 10. Boron is contained in an amount of at least 0.011% by mass and up to 0.6% by mass relative to the entire amount of the positive electrode active material.

First claim

1 . A positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising:
a lithium-nickel composite oxide represented by a general formula: Li a Ni 1−x−y Co x M y O 2+α (where 0.01≤x≤0.35, 0≤y≤0.10, 0.95≤a≤1.10, and 0≤α≤0.2; and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al); and a boron compound, wherein at least part of the boron compound is present on a surface of the lithium-nickel composite oxide in the form of Li 3 BO 3 and LiBO 2 , and a mass ratio (Li 3 BO 3 /LiBO 2 ) between Li3BO3 and LiBO2 is at least 0.005 and up to 10, and boron is contained in an amount of at least 0.011% by mass and up to 0.6% by mass relative to an entire amount of the positive electrode active material.

2 . A method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery, the method comprising:
mixing a nickel composite hydroxide or a nickel composite oxide, a lithium compound, and a first boron compound capable of reacting with lithium together so as to give a boron amount A in the first boron compound of at least 0.001% by mass and up to 0.1% by mass relative to an entire amount of a positive electrode active material to obtain a lithium mixture; firing the lithium mixture in an oxygen atmosphere at at least 700° C. and up to 800° C. to obtain a first lithium-nickel composite oxide; and mixing the first lithium-nickel composite oxide and a second boron compound capable of reacting with lithium with each other so as to give a boron amount B in the second boron compound of at least 0.01% by mass and up to 0.5% by mass relative to the entire amount of the positive electrode active material and so as to give a ratio (AB) between the boron amount A in the first boron compound and the boron amount B in the second boron compound of at least 0.005 and up to 10 to obtain a second lithium-nickel composite oxide, wherein the first boron compound and the second boron compound are the same compound or different compounds, and the second lithium-nickel composite oxide is represented by a general formula Li a Ni 1−x−y Co x M y O 2+α (where 0.01≤x≤0.35, 0≤y≤0.10, 0.95≤a≤1.10, and 0≤α≤0.2; and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al) and has Li 3 BO 3 and LiBO 2 on a surface thereof.

3 . The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein the first boron compound contains at least one selected from H 3 BO 3 , B 2 O 3 , and LiBO 2 .

4 . The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 2 , wherein the second boron compound contains either one or both of H 3 BO 3 and B 2 O 3 .

5 . A positive electrode mixture paste for a nonaqueous electrolyte secondary battery, the positive electrode mixture paste comprising the positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 .

6 . A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte, the positive electrode comprising the positive electrode active material according to claim 1 .

Assignees

• Sumitomo Metal Mining Co

Inventors

• Ryoshi Kazuomi
• Otsuka Yoshihiro
• Oshita Hiroko

Classifications

• H01M4/525 Primary

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

• C01G53/42

  containing alkali metals, e.g. LiNiO2 · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• C01P2006/40

  Electric properties · CPC title