Method of preparing positive electrode material for lithium secondary battery, positive electrode material for lithium secondary battery, and lithium secondary battery including the positive electrode material

Patent metadata

Field	Value
Publication number	US-10938036-B2
Application number	US-201514907990-A
Country	US
Kind code	B2
Filing date	Sep 10, 2015
Priority date	Sep 12, 2014
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

The present invention relates to a method of preparing a positive electrode material for a lithium secondary battery including a first step of synthesizing a lithium transition metal oxide represented by Chemical Formula 1, a second step of preparing lithium transition metal oxide powder by grinding the lithium transition metal oxide, a third step of preparing a positive electrode material including an alumina coating layer by mixing as well as dispersing the lithium transition metal oxide powder in an alumina nanosol, and a fourth step of drying the positive electrode material, a positive electrode material for a lithium secondary battery prepared by the above method, and a lithium secondary battery including the positive electrode material,

Li (1+a) (Ni (1−a−b−c) Mn b Co c )O n   [Chemical Formula 1]
where 0≤a≤0.1, 0≤b≤1, 0<c≤1, and n is an integer of 2 or 4.

First claim

The invention claimed is:

1. A method of preparing a positive electrode material for a lithium secondary battery, the method comprising steps of:
a first step of synthesizing a lithium transition metal oxide represented by Chemical Formula 1;
a second step of preparing lithium transition metal oxide powder by grinding the lithium transition metal oxide so that a particle diameter of the lithium transition metal oxide powder is in a range of 10 μm to 30 μm after the grinding;
a third step of preparing a positive electrode material including an alumina coating layer by mixing as well as dispersing the lithium transition metal oxide powder in an alumina nanosol, wherein the alumina nanosol is prepared by a method including: mixing alumina nanopowder and a solvent to prepare an alumina nanopowder suspension; and dispersing the suspension to prepare the alumina nanosol, wherein the alumina nanosol includes a γ-alumina phase in an amount of 99% or more;
wherein the lithium transition metal oxide powder and the alumina nanosol are mixed in a weight ratio of 1:80 to 1:100;
wherein the lithium transition metal oxide powder is dispersed in the alumina nanosol is after a lithium transition metal oxide powder solution is prepared by spraying the lithium transition metal oxide powder in an organic solvent;
a fourth step of drying the positive electrode material in a temperature range of 100° C. to 350° C.,

a fifth step of sintering the positive electrode material in a temperature range of 400° C. to 1200° C., after the drying in the fourth step; and
Li (1+a) (Ni (1−a−b−c) Mn b Co c )O n   [Chemical Formula 1]

where 0≤a≤0.1, 0≤b≤1, 0<c≤1, a+b+c≤1, and n is an integer of 2 or 4.

2. The method of claim 1 , wherein the alumina coating layer comprises the γ-alumina phase in an amount of 95 wt % or more based on a total weight of the alumina coating layer.

3. The method of claim 1 , wherein the lithium transition metal oxide is Li(Ni 0.6 Mn 0.2 Co 0.2 O 2 ), Li(Ni 0.8 Mn 0.1 Co 0.1 O 2 ), Li(Ni 0.5 Mn 0.3 Co 0.2 O 2 ), Li(Ni 1/3 Mn 1/3 Co 1/3 O 2 ), or LiCoO 2 .

4. The method of claim 1 , wherein the organic solvent is 1-methoxy-2-propanol, ethyl alcohol, methyl alcohol, or isopropyl alcohol.

5. The method of claim 1 , wherein the organic solvent is used in an amount of 70 wt % to 99 wt % based on a total weight of the positive electrode material.

Assignees

• Lg Chemical Ltd

Inventors

• Kwak Ick Soon
• Cho Seung Beom
• Yoon Yeo June
• Mhin Sung Wook

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title