Positive Electrode Active Material, Method for Manufacturing Positive Electrode Active Material, and Secondary Battery

Patent metadata

Field	Value
Publication number	US-2020358091-A1
Application number	US-202016940890-A
Country	US
Kind code	A1
Filing date	Jul 28, 2020
Priority date	Nov 18, 2016
Publication date	Nov 12, 2020
Grant date	—

Abstract

Provided is a positive electrode active material for a lithium ion secondary battery having favorable cycle characteristics and high capacity. A covering layer containing aluminum and a covering layer containing magnesium are provided on a superficial portion of the positive electrode active material. The covering layer containing magnesium exists in a region closer to a particle surface than the covering layer containing aluminum is. The covering layer containing aluminum can be formed by a sol-gel method using an aluminum alkoxide. The covering layer containing magnesium can be formed as follows: magnesium and fluorine are mixed as a starting material and then subjected to heating after the sol-gel step, so that magnesium is segregated.

First claim

What is claimed is:

1 . A lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and an exterior body,
wherein the positive electrode comprises a positive electrode active material comprising a composite oxide containing lithium and cobalt, wherein the positive electrode active material comprises aluminum, magnesium, and fluorine, wherein in line analysis of energy dispersive X-ray spectrometry, a peak of a concentration of the magnesium exists in a region from a surface of the positive electrode active material to a depth of 3 nm, wherein the peak of the concentration of the magnesium is positioned closer to the surface of the positive electrode active material than a peak of a concentration of the aluminum is, wherein the negative electrode comprises a negative electrode active material, and wherein the negative electrode active material comprises a carbon-based material.

2 . A lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and an exterior body,
wherein the positive electrode comprises a positive electrode active material comprising a composite oxide containing lithium and cobalt, wherein the positive electrode active material comprises aluminum, magnesium, and fluorine, wherein in line analysis of energy dispersive X-ray spectrometry, a peak of a concentration of the magnesium exists in a region from a surface of the positive electrode active material to a depth of 3 nm, wherein the peak of the concentration of the magnesium and a peak of a concentration of the fluorine are positioned closer to the surface of the positive electrode active material than a peak of a concentration of the aluminum is, wherein the negative electrode comprises a negative electrode active material, and wherein the negative electrode active material comprises a carbon-based material.

3 . A lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and an exterior body,
wherein the positive electrode comprises a positive electrode active material comprising a composite oxide containing lithium and cobalt, wherein the positive electrode active material comprises aluminum, magnesium, and fluorine, wherein in line analysis of energy dispersive X-ray spectrometry, a peak of a concentration of the magnesium exists in a region from a surface of the positive electrode active material to a depth of 3 nm, wherein the negative electrode comprises a negative electrode active material, and wherein the negative electrode active material comprises a carbon-based material.

4 . The lithium-ion secondary battery according to claim 3 ,
wherein the magnesium comprises a region existing closer to the surface of the positive electrode active material than the aluminum is.

5 . The lithium-ion secondary battery according to claim 3 ,
wherein the magnesium and the fluorine comprise a region existing closer to the surface of the positive electrode active material than the aluminum is.

6 . A lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and an exterior body,
wherein the positive electrode comprises a positive electrode active material comprising a composite oxide containing lithium and cobalt, wherein the positive electrode active material comprises aluminum, magnesium, and fluorine, wherein in line analysis of energy dispersive X-ray spectrometry, a peak of a concentration of the magnesium and a peak of a concentration of the fluorine exist in a region from a surface of the positive electrode active material to a depth of 3 nm, wherein the peak of the concentration of the magnesium is positioned closer to the surface of the positive electrode active material than a peak of a concentration of the aluminum is, wherein the negative electrode comprises a negative electrode active material, and wherein the negative electrode active material comprises a carbon-based material.

7 . A lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and an exterior body,
wherein the positive electrode comprises a positive electrode active material, wherein the positive electrode active material comprises cobalt, aluminum, magnesium, and fluorine, wherein in line analysis of energy dispersive X-ray spectrometry, a peak of a concentration of the magnesium and a peak of a concentration of the fluorine exist in a region from a surface of the positive electrode active material to a depth of 3 nm, wherein the peak of the concentration of the magnesium and a peak of a concentration of the fluorine are positioned closer to the surface of the positive electrode active material than a peak of a concentration of the aluminum is, wherein the negative electrode comprises a negative electrode active material, and wherein the negative electrode active material comprises a carbon-based material.

8 . A lithium-ion secondary battery comprising a positive electrode, a negative electrode, an electrolyte, and an exterior body,
wherein the positive electrode comprises a positive electrode active material comprising a composite oxide containing lithium and cobalt, wherein the positive electrode active material comprises aluminum, magnesium, and fluorine, wherein in line analysis of energy dispersive X-ray spectrometry, a peak of a concentration of the magnesium and a peak of a concentration of the fluorine exist in a region from a surface of the positive electrode active material to a depth of 3 nm, wherein the negative electrode comprises a negative electrode active material, and wherein the negative electrode active material comprises a carbon-based material.

9 . The lithium-ion secondary battery according to claim 8 ,
wherein the magnesium comprises a region existing closer to the surface of the positive electrode active material than the aluminum is.

10 . The lithium-ion secondary battery according to claim 8 ,
wherein the magnesium and the fluorine comprise a region existing closer to the surface of the positive electrode active material than the aluminum is.

11 . The lithium-ion secondary battery according to claim 1 ,
wherein the carbon-based material is graphite.

12 . The lithium-ion secondary battery according to claim 2 ,
wherein the carbon-based material is graphite.

13 . The lithium-ion secondary battery according to claim 3 ,
wherein the carbon-based material is graphite.

14 . The lithium-ion secondary battery according to claim 6 ,
wherein the carbon-based material is graphite.

15 . The lithium-ion secondary battery according to claim 7 ,
wherein the carbon-based material is graphite.

16 . The lithium-ion secondary battery according to claim 8 ,
wherein the carbon-based material is graphite.

17 . The lithium-ion secondary battery according to claim 1 ,
wherein the electrolyte comprises LiPF 6 .

18 . The lithium-ion secondary battery according to claim 2 ,
wherein the electrolyte comprises LiPF 6 .

19 . The lithium-ion secondary battery according to claim 3 ,
wherein the electrolyte comprises LiPF 6 .

20 . The lithium-ion secondary battery according to claim 6 ,
wherein the electrolyte comprises LiPF 6 .

21 . The lithium-ion secondary battery according to claim 7 ,
wherein the electrolyte comprises LiPF 6 .

22 . The lithium-ion secondary battery according to claim 8 ,
wherein the elec

Assignees

• Semiconductor Energy Lab

Inventors

• Momma Yohei
• Kawakami Takahiro
• Ochiai Teruaki
• Takahashi Masahiro

Classifications

• 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

• H01M2004/021

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

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• H01M4/625

  Carbon or graphite · CPC title