Positive electrode active material for nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10418626-B2
Application number	US-201515320114-A
Country	US
Kind code	B2
Filing date	Aug 5, 2015
Priority date	Aug 26, 2014
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery capable of suppressing a decrease in the capacity retention ratio after high-temperature cycles. There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery that includes a secondary particle formed by aggregation of primary particles formed of a lithium transition metal oxide. A rare-earth compound secondary particle formed by aggregation of particles formed of a rare-earth compound adheres to a recess formed between primary particles adjacent to each other on a surface of the secondary particle, and the rare-earth compound secondary particle adheres to both the primary particles adjacent to each other in the recess. The lithium transition metal oxide contains tungsten dissolved therein.

First claim

The invention claimed is:

1. A positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising lithium transition metal oxide secondary particles formed by aggregation of primary particles of the lithium transition metal oxide,
wherein a rare-earth compound tertiary particle formed by aggregation of initial particles formed of a rare-earth compound is adhered to a recess formed between adjacent primary particles on a surface of the secondary particle, and the rare-earth compound tertiary particle adheres to at least two adjacent primary particles forming the recess,
the lithium transition metal oxide comprises nickel and/or cobalt and contains tungsten dissolved therein; and
wherein the rare-earth compound is at least one compound selected from the group consisting of hydroxides and oxyhydroxides.

2. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the rare-earth compound contains a rare-earth element, and the rare-earth element is at least one element selected from the group consisting of neodymium, samarium, and erbium.

3. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein a proportion of nickel in the lithium transition metal oxide is 80 to 94 mol % based on a total molar quantity of metal elements other than lithium.

4. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein a proportion of cobalt in the lithium transition metal oxide is 1 to 7 mol % or less based on a total molar quantity of metal elements other than lithium.

5. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 ,
wherein the rare-earth compound contains a rare-earth element, and the rare-earth element is at least one element selected from the group consisting of neodymium, samarium, and erbium,
wherein the lithium transition metal oxide comprises nickel and a proportion of nickel in the lithium transition metal oxide is 80 to 94 mol % based on a total molar quantity of metal elements other than lithium.

6. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 5 , wherein the lithium transition metal oxide comprises cobalt and a proportion of cobalt in the lithium transition metal oxide is 1 to 7 mol % based on a total molar quantity of metal elements other than lithium.

Assignees

• Sanyo Electric Co

Inventors

• Kawakita Akihiro
• Ogasawara Takeshi
• Jito Daizo

Classifications

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M4/505

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

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M4/366 Primary

  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