Positive electrode active substance particles comprising lithium nickelate composite oxide, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2020185708-A1
Application number	US-201816617161-A
Country	US
Kind code	A1
Filing date	Jul 13, 2018
Priority date	Jul 14, 2017
Publication date	Jun 11, 2020
Grant date	—

Abstract

The present invention provides positive electrode active substance particles comprising a lithium nickelate composite oxide which have a high energy density and which are excellent in repeated charge/discharge cycle characteristics upon charging at a high voltage when used in a secondary battery, as well as a non-aqueous electrolyte secondary battery. The present invention relates to positive electrode active substance particles each comprising: a core particle X comprising a lithium nickelate composite oxide having a layer structure which is represented by the formula of Li1+aNi1−b−cCObMcO2 wherein M is at least one element selected from the group consisting of Mn, Al, B, Mg, Ti, Sn, Zn and Zr; a is a number of −0.1 to 0.2 (−0.1≤a≤0.2); b is a number of 0.05 to 0.5 (0.05≤b≤0.5); and c is a number of 0.01 to 0.4 (0.01≤c≤0.4); and a coating compound Y comprising at least one element selected from the group consisting of Al, Mg, Zr, Ti and Si, in which the coating compound Y has an average film thickness of 0.2 to 5 nm, a degree of crystallinity of 50 to 95%, a degree of epitaxy of 50 to 95% and a coating ratio (coverage) of 50 to 95%.

First claim

1 . Positive electrode active substance particles each comprising:
a core particle X comprising a lithium nickelate composite oxide having a layer structure which is represented by the formula:
Li 1+a Ni 1−b−c CO b M c O 2
wherein M is at least one element selected from the group consisting of Mn, Al, B, Mg, Ti, Sn, Zn and Zr; a is a number of −0.1 to 0.2 (−0.1≤a≤0.2); b is a number of 0.05 to 0.5 (0.05≤b≤0.5); and c is a number of 0.01 to 0.4 (0.01≤c≤0.4); and
a coating compound Y comprising at least one element selected from the group consisting of Al, Mg, Zr, Ti and Si, in which the coating compound Y has an average film thickness of 0.2 to 5 nm, a degree of crystallinity of 50 to 95%, a degree of epitaxy of 50 to 95% and a coating ratio (coverage) of 50 to 95%.

2 . The positive electrode active substance particles according to claim 1 , wherein an average value of a ratio of a total number of atoms of elements Al, Mg, Zr, Ti and Si in the coating compound Y to a number of atoms of an element Ni in the coating compound Y is not less than 0.5.

3 . The positive electrode active substance particles according to claim 1 , wherein a content of lithium hydroxide LiOH in the positive electrode active substance particles is not more than 0.50% by weight; a content of lithium carbonate Li 2 CO 3 in the positive electrode active substance particles is not more than 0.65% by weight; and a weight ratio of the content of lithium carbonate to the content of lithium hydroxide is not less than 0.9.

4 . The positive electrode active substance particles according to claim 1 , wherein the positive electrode active substance particles have a BET specific surface area of 0.05 to 0.70 m 2 /g, a median diameter D 50 of aggregated particles of 1 to 30 μm, and a 2% powder pH value of not more than 11.6.

5 . A non-aqueous electrolyte secondary battery comprising a positive electrode active substance comprising at least partially the positive electrode active substance particles according to claim 1 .

Assignees

• Toda Kogyo Corp

Inventors

• Watanabe Hiroyasu
• Sun Xiang

Classifications

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• C01P2006/12

  Surface area · CPC title

• C01G53/42 Primary

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

• C01P2006/40

  Electric properties · CPC title

• C01P2004/86

  Thin layer coatings, i.e. the coating thickness being less than 0.1 time the particle radius · CPC title