Positive electrode active material for non-aqueous electrolyte secondary battery and method for manufacturing the same, positive electrode mixed material paste for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2019165360-A1
Application number	US-201716301808-A
Country	US
Kind code	A1
Filing date	May 12, 2017
Priority date	May 16, 2016
Publication date	May 30, 2019
Grant date	—

Abstract

The present invention has an object to provide a positive electrode active material for a non-aqueous electrolyte secondary battery which not only suppresses gelation of a positive electrode mixed material paste upon producing the non-aqueous electrolyte secondary battery but also improves the stability thereof. Provided is the positive electrode active material represented by general formula Li s Ni 1−x−y−z Co x Mn y M z O 2+α (0≤x≤0.35, 0≤y≤0.35, 0≤z≤0.10, 0.95≤s≤1.30, and 0≤α≤0.2, and M represents at least one element selected from V, Mg, Mo, Nb, Ti, W, and Al) and containing secondary particles formed by agglomeration of primary particles, wherein at least part of the surface of the primary particles thereof is covered with a lithium boron compound, and the amount of redundant lithium hydroxide of the positive electrode active material measured with a neutralization titration is at least 0.003% by mass and up to 0.5% by mass relative to the total of the positive electrode active material.

First claim

1 . A positive electrode active material for a non-aqueous electrolyte secondary battery, the positive electrode active material comprising:
a lithium-metal composite oxide represented by a general formula Li s Ni 1−x−y−z Co x Mn y M z O 2+α (where 0≤x≤0.35, 0≤y≤0.35, 0≤z≤0.10, 0.95<s<1.30, and 0≤α≤0.2, and M represents at least one element selected from V, Mg, Mo, Nb, Ti, W, and Al) and a lithium boron compound, wherein the lithium-metal composite oxide comprises a secondary particle formed by agglomeration of primary particles, at least part of the surface of the primary particles is covered with the lithium boron compound, and the amount of an eluted lithium hydroxide measured with a neutralization titration method upon dispersing the positive electrode active material in water is at least 0.003% by mass and up to 0.5% by mass in terms of Li relative to the total of the positive electrode active material.

2 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the amount of boron included in the lithium boron compound is at least 0.03% by mole and up to 8% by mole relative to the total of Ni, Co, Mn, and M in the positive electrode active material.

3 . The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the lithium boron compound comprises lithium borate.

4 . A method for manufacturing a positive electrode active material for a non-aqueous electrolyte secondary battery, the method comprising:
mixing fired powder comprising a lithium-metal composite oxide having a crystal structure of a layered structure, a boron compound not including lithium but being capable of reacting with lithium, and water; and drying the resultant mixture obtained by the mixing to obtain a positive electrode active material, wherein the fired powder is represented by a general formula Li s Ni 1−x−y−z Co x Mn y M z O 2+α (where 0≤x≤0.35, 0≤y≤0.35, 0≤z≤0.10, 0.95<s<1.30, and 0≤α≤0.2, and M represents at least one element selected from V, Mg, Mo, Nb, Ti, W, and Al) and contains a secondary particle formed by agglomeration of primary particles, and the boron compound is mixed such that the amount of an eluted lithium hydroxide measured with a neutralization titration method upon dispersing the positive electrode active material in water is at least 0.003% by mass and up to 0.5% by mass relative to the total of the positive electrode active material.

5 . The method for manufacturing the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 4 , wherein after mixing the boron compound with the fired powder, the water is added to the resultant mixture with an amount thereof being at least 1% by mass and up to 40% by mass relative to the fired powder.

6 . The method for manufacturing the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 4 , wherein the drying is carried out at least 100° C. and up to 300° C.

7 . The method for manufacturing the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 4 , wherein the surface of the primary particles of the positive electrode active material is covered with a lithium boron compound.

8 . The method for manufacturing the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 4 , wherein the boron compound comprises at least one of boric acid, boron oxide, and ammonium borate.

9 . The method for manufacturing the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 4 , wherein an addition amount of boron included in the boron compound is at least 0.03% by mole and up to 8% by mole relative to the total of Ni, Co, Mn, and M in the fired powder.

10 . Positive electrode mixed material paste for a non-aqueous electrolyte secondary battery, the positive electrode mixed material paste comprising the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 .

11 . A non-aqueous electrolyte secondary battery comprising a positive electrode that comprises the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 .

Assignees

• Sumitomo Metal Mining Co

Inventors

• Saruwatari Motoaki
• Ryoshi Kazuomi

Classifications

• C01P2004/84

  one phase coated with the other · CPC title

• C01P2004/50

  Agglomerated particles · CPC title

• C01B35/121

  of alkali metal · CPC title

• H01M4/505

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

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title