Positive electrode active material for nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2017141384-A1
Application number	US-201515320114-A
Country	US
Kind code	A1
Filing date	Aug 5, 2015
Priority date	Aug 26, 2014
Publication date	May 18, 2017
Grant date	—

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

1 . A positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising a secondary particle formed by aggregation of primary particles formed of a lithium transition metal oxide,
wherein 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, and the lithium transition metal oxide contains tungsten dissolved therein.

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 the rare-earth compound is at least one compound selected from the group consisting of hydroxides and oxyhydroxides.

4 . 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 mol % or more 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 a proportion of cobalt in the lithium transition metal oxide is 7 mol % or less 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 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 a proportion of nickel in the lithium transition metal oxide is 80 mol % or more based on a total molar quantity of metal elements other than lithium.

7 . 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 rare-earth compound is at least one compound selected from the group consisting of hydroxides and oxyhydroxides, wherein a proportion of nickel in the lithium transition metal oxide is 80 mol % or more based on a total molar quantity of metal elements other than lithium.

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

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

Assignees

• Sanyo Electric Co

Inventors

• Kawakita Akihiro
• Ogasawara Takeshi
• Jito Daizo

Classifications

• H01M4/505

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

• H01M4/483

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

• H01M4/366 Primary

  as layered products · CPC title

• H01M2004/028

  Positive electrodes · CPC title