Lithium-iron-manganese-based composite oxide and lithium-ion secondary battery using same

Patent metadata

Field	Value
Publication number	US-10847788-B2
Application number	US-201615551853-A
Country	US
Kind code	B2
Filing date	Feb 9, 2016
Priority date	Feb 20, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is suppressed. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula is coated with an oxide of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu:

Li x M 1 (y-p) Mn p M 2 (z-q) Fe q O (2-δ)

wherein 1.05≤x≤1.32, 0.33≤y≤0.63, 0.06≤z≤0.50, 0<p≤0.63, 0.06≤q≤0.50, 0≤δ≤0.80, y≥p, and z≥q; M 1 is at least one element selected from Ti and Zr; and M 2 is at least one element selected from the group consisting of Co, Ni and Mn.

First claim

The invention claimed is:

1. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of a surface of the lithium-iron-manganese-based composite oxide represented by the following formula (1) is coated with a mixture of an oxide A of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu and an oxide B of at least one metal selected from the group consisting of Ge, Mo, Zr, Al and V:
Li x M 1 (y-p) Mn p M 2 (z-q) Fe q O (2-δ)   (1)

wherein 1.05≤x≤1.32, 0.33≤y≤0.63, 0.06≤z≤0.50, 0<≤p≤0.63, 0.06≤q≤0.50, 0≤δ≤0.80, y≥p, and z≥q; M 1 is at least one element selected from the group consisting of Ti and Zr; and M 2 is at least one element selected from the group consisting of Co, Ni
wherein, in the formula (1), q satisfies 0.16≤q≤0.45,and
wherein a mixing ratio between the oxide A and the oxide B (oxide A : oxide B) is 1:0.5 to 1:2.0.

2. A positive electrode active material for a lithium-ion secondary battery, wherein the positive electrode active material comprises the lithium-iron-manganese-based composite oxide according to claim 1 .

3. A positive electrode for a lithium-ion secondary battery, wherein the positive electrode comprises the positive electrode active material according to claim 2 .

4. A lithium-ion secondary battery comprising the positive electrode according to claim 3 and a negative electrode.

5. The lithium-ion secondary battery according to claim 4 , wherein the negative electrode comprises SiO as a negative electrode active material.

6. The lithium-ion secondary battery according to claim 4 , wherein in the formula (1), δ satisfies 0≤δ≤0.50.

7. The lithium-ion secondary battery according to claim 4 , wherein in the formula (1), δ=0.

8. The lithium-iron-manganese-based composite oxide according to claim 1 , wherein a content of the coated mixture is 1% by mass or more and 15% by mass or less.

9. The lithium-iron-manganese-based composite oxide according to claim 1 , wherein, in the formula (1), δ satisfies 0≤δ≤0.50.

10. The lithium-iron-manganese-based composite oxide according to claim 1 , wherein, in the formula (1), δ=0.

11. A lithium-ion secondary battery comprising a positive electrode and a negative electrode,
wherein the positive electrode comprises a positive electrode active material comprising a lithium-iron-manganese-based composite oxide represented by the following formula (1):
Li x M 1 (y-p) Mn p M 2 (z-q) Fe q O (2-δ)   ( 1 )

wherein 1.05≤x≤1.32, 0.33≤y≤0.63, 0.06≤z≤0.50, 0<≤p≤0.63, 0.06≤q≤0.50, 0≤δ≤0.80, y≥p, and z≥q; M 1 is at least one element selected from the group consisting of Ti and Zr; and M 2 is at least one element selected from the group consisting of Co, Ni
at least a part of a surface of the lithium-iron-manganese-based composite oxide is coated with a mixture of an oxide A of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu and an oxide B of at least one metal selected from the group consisting of Ge, Mo, Zr, Al and V;
a mixing ratio between the oxide A and the oxide B (oxide A : oxide B) is 1:0.5 to 1:2.0;
wherein a content of the coated mixture is 1% by mass or more and 15% by mass or less; and
the negative electrode comprises SiO as a negative electrode active material.

12. The lithium-ion secondary battery according to claim 11 , wherein in the formula (1), δ satisfies 0≤δ≤0.50.

13. The lithium-ion secondary battery according to claim 11 , wherein in the formula (1), δ=0.

Assignees

• Nec Corp
• Tanaka Chemical Corp

Inventors

• Yuge Ryota
• Tamura Noriyuki
• Hattori Sadanori
• Tabuchi Mitsuharu
• Kuratani Kentaro
• Doumae Kyousuke
• Shibuya Hideka

Classifications

• C01F17/229

  Lanthanum oxides or hydroxides · CPC title

• C01F17/224

  Oxides or hydroxides of lanthanides · 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

• C01P2004/84

  one phase coated with the other · CPC title

• C01P2004/03

  obtained by SEM · CPC title