Positive electrode active material for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery using the positive electrode active material

Patent metadata

Field	Value
Publication number	US-2018337403-A1
Application number	US-201615771147-A
Country	US
Kind code	A1
Filing date	Oct 3, 2016
Priority date	Oct 26, 2015
Publication date	Nov 22, 2018
Grant date	—

Abstract

A positive electrode active material for a nonaqueous electrolyte secondary battery is provided, which can establish both high capacity and high output when used for a positive electrode material.
A positive electrode active material for a nonaqueous electrolyte secondary battery comprises primary particles of a lithium-nickel composite oxide represented by the following general formula (1) and secondary particles composed by aggregation of the primary particles, wherein a 1-nm to 200-nm thick film containing W and Li is present on the surface of the primary particles, and a c-axis length in the LiNi composite oxide crystal ranges from 14.183 to 14.205 angstroms.
General formula: Li b Ni 1-x-y Co x M y O 2   (1)

(In the formula, M is at least one type of element selected from Mg, Al, Ca, Ti, V, Cr, Mn, Nb, Zr and Mo, and 0.95≤b≤1.03, 0<x≤0.15, 0<y≤0.07, and x+y≤0.16 are satisfied.)

First claim

1 . A positive electrode active material for a nonaqueous electrolyte secondary battery, comprising primary particles of a lithium-nickel composite oxide represented by the following general formula (1) and secondary particles composed by aggregation of the primary particles, wherein
a film having a thickness of 1 nm to 200 nm and containing W and Li is present on the surface of the primary particles, and a c-axis length in the crystal of the lithium-nickel composite oxide is 14.183 angstroms or more and 14.205 angstroms or less, as determined by Rietveld analysis on X-ray diffraction.
(Chemical Formula 1)
General formula: Li b Ni 1-x-y Co x M y O 2   (1)

(In the formula, M is at least one type of element selected from Mg, Al, Ca, Ti, V, Cr, Mn, Nb, Zr and Mo, b is a numerical value satisfying 0.95≤b≤1.03, x is a numerical value satisfying 0<x≤0.15, y is a numerical value satisfying 0<y≤0.07, and x+y is a numerical value satisfying x+y≤0.16.)

2 . The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein void parts to be determined by the cross-sectional observation of the secondary particles are portions where the lithium-nickel composite oxide represented by general formula (1) is absent in the cross section of the secondary particles, and a porosity calculated with the void parts ranges from 0.5% to 4.0%.

3 . The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the number of tungsten atoms contained in the film containing tungsten and lithium accounts for 0.1 atom % to 3.0 atom % with respect to the total number of Ni, Co and M atoms contained in the lithium-nickel composite oxide of the primary particles.

4 . The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , which is represented by the following general formula (2).
(Chemical Formula 2) General formula: Li b Ni 1-x-y Co x M y W z O 2+α   (2)

(In the formula, M is at least one type of element selected from Mg, Al, Ca, Ti, V, Cr, Mn, Nb, Zr and Mo, and b is a numerical value satisfying 0.95<b≤1.10, x is a numerical value satisfying 0<x≤0.15, y is a numerical value satisfying 0<y≤0.07, x+y is a numerical value satisfying x+y≤0.16, z is a numerical value satisfying 0.001≤z≤0.03, and α is a numerical value satisfying 0≤α≤0.2.)

5 . The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein W and Li contained in the film are present in the form of lithium tungstate.

6 . The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium-nickel composite oxide has a mean particle diameter ranging from 5 μm to 30 μm.

7 . The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , which has the film on the surface of the primary particles, and has fine particles containing tungsten and lithium and having a diameter ranging from 1 nm to 200 nm.

8 . A nonaqueous electrolyte secondary battery, which has a positive electrode containing the positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 .

Assignees

• Sumitomo Metal Mining Co

Inventors

• Komukai Tetsufumi
• Furuichi Yuki

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• C01G53/42

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

• H01M2004/028

  Positive electrodes · CPC title

• 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