Positive electrode active material for non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-11811052-B2
Application number	US-201917042431-A
Country	US
Kind code	B2
Filing date	Mar 28, 2019
Priority date	Mar 29, 2018
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

The present invention provides a positive electrode active material for a non-aqueous electrolyte secondary battery including a lithium metal composite oxide powder represented by a general formula: Li z Ni 1−x−y Co x M y O 2+α , wherein 0<x≤0.35, 0≤y≤0.35, 0.95≤z≤1.30, −0.15≤α≤0.15, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti and Al; and a coating layer placed on particle surfaces of the lithium metal composite oxide powder; wherein the coating layer is a mixed-phase of a crystalline phase and an amorphous phase.

First claim

The invention claimed is:

1. A positive electrode active material for a non-aqueous electrolyte secondary battery comprising:
a lithium metal composite oxide powder represented by a general formula:
Li z Ni 1−x−y Co x M y O 2−α ,

wherein 0<x≤0.35, 0≤y≤0.35, 0.95≤z≤1.30, −0.15≤α≤0.15, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti and Al; and
a coating layer placed on particle surfaces of the lithium metal composite oxide powder;
wherein the coating layer is a mixed-phase of a crystalline phase and an amorphous phase.

2. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 ,
wherein an amorphous-phase/crystalline-phase ratio of the coating layer is 0.05 or more and 100 or less, and
the ratio is calculated by:
an electron diffraction pattern acquisition step in which an electron diffraction pattern of the coating layer is acquired using a transmission electron microscope-electron diffraction pattern;
a diffraction intensity calculation step wherein a diffraction intensity pattern in a one-dimensional region is extracted from the acquired electron diffraction pattern, and an integral value Ic of a diffraction intensity of a crystalline phase region derived from a (lmn) plane which is a crystalline plane having a highest diffraction intensity of a crystalline phase contained in the coating layer and an integral value Ia of a diffraction intensity of an amorphous phase region derived from an amorphous phase contained in the coating layer are calculated from the acquired diffraction intensity pattern;
a normalization step in which a normalized integral value Ics is calculated by dividing the integral value Ic by a ratio of a diffraction intensity of the (lmn) plane when a diffraction intensity of a crystalline plane having a highest diffraction intensity in a powder X-ray diffraction pattern of the crystalline phase is regarded as 1; and
a ratio calculation step in which a ratio of the integral value Ia to the normalized integral value Ics is calculated to obtain an amorphous-phase/crystalline-phase ratio of the coating layer.

3. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the coating layer contains lithium tungstate.

4. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 2 , wherein the coating layer contains lithium tungstate.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Okada Jiro
• Komukai Tetsufumi
• Yokoyama Jun
• Ogawa Takahiro
• Nakayama Tomoko

Classifications

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title

• C01G53/50

  of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 · CPC title

• H01M4/131 Primary

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

• H01M4/366

  as layered products · CPC title

• H01M4/505

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