Nonaqueous electrolyte secondary battery positive electrode active material and method for producing same, and nonaqueous electrolyte secondary battery which uses positive electrode active material

Patent metadata

Field	Value
Publication number	US-11967709-B2
Application number	US-201816760130-A
Country	US
Kind code	B2
Filing date	Jul 31, 2018
Priority date	Oct 31, 2017
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

The present invention provides a composite oxide that can achieve a high low-temperature output characteristic, a method for manufacturing the same, and a positive electrode active material in which the generation of soluble lithium is suppressed and a problem of gelation is not caused during the paste preparation. A positive electrode active material for non-aqueous electrolyte secondary batteries, including a lithium-metal composite oxide powder including a secondary particle configured by aggregating primary particles containing lithium, nickel, manganese, and cobalt, or a lithium-metal composite oxide powder including both the primary particles and the secondary particle, wherein the secondary particle has a hollow structure inside as a main inside structure, the slurry pH is 11.5 or less, the soluble lithium content rate is 0.5 [% by mass] or less, the specific surface area is 2.0 to 3.0 [m 2 /g], and the porosity is 20 to 50 [%].

First claim

The invention claimed is:

1. A positive electrode active material for non-aqueous electrolyte secondary batteries, the positive electrode active material comprising:
a lithium-metal composite oxide powder comprising a plurality of secondary particles, each secondary particle comprising a plurality of primary particles containing lithium, nickel, manganese, and cobalt, wherein
each secondary particle in the plurality of secondary particles comprises a plurality of hollow structures,
a mixed slurry being a mixture of water and the lithium-metal composite oxide powder as a slurry solid body component has a pH of 11.5 or less at a time when the mixed slurry contains the lithium-metal composite oxide powder at a slurry concentration of 50 [g/L],
the lithium-metal composite oxide powder contains soluble lithium at a content rate of 0.5 [% by mass] or less,
the lithium-metal composite oxide powder is represented by a general formula: Li a (Ni 1-w-x Mn w Co x ) 1-y M y O 2 : 0.98≤a≤1.20, 0.01≤w≤0.50, 0.01≤x≤0.50, 0.01≤y≤0.10, where M is one or more of Fe, Cu, Si, Zn,
the lithium-metal composite oxide powder has a particle strength of 150 to 180 MPa,
the lithium-metal composite oxide powder has a specific surface area of 2.0 to 3.0 [m 2 /g], and
the secondary particle has a porosity of 20 to 50 [%].

2. A non-aqueous electrolyte secondary battery comprising a positive electrode including the positive electrode active material for non-aqueous electrolyte secondary batteries according to claim 1 , wherein
ΔV −20[°C.] determined by a current rest method is 0.55 [V] or less at −20 [° C.].

3. A positive electrode mixture paste for non-aqueous electrolyte secondary batteries, the positive electrode mixture paste comprising:
a solid component; and
a solvent, wherein
the solid component contains the positive electrode active material for non-aqueous electrolyte secondary batteries according to claim 1 , and
the positive electrode mixture paste has a viscosity of 5,000 [mPa·s] or less at 20 [° C.] at a time when the solid component and the solvent have a mass ratio of the solid component [g]/the solvent [g]=1.875.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Oshita Hiroko
• Ryoshi Kazuomi
• Aida Taira
• Yamaji Koji
• Okada Jiro

Classifications

• H01M4/505 Primary

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

• H01M4/0471 Primary

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

• H01M4/362

  Composites · CPC title

• H01M4/366

  as layered products · 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