Cathode active material for lithium secondary battery and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-9761875-B2
Application number	US-201414420057-A
Country	US
Kind code	B2
Filing date	Feb 14, 2014
Priority date	Feb 14, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

The present disclosure relates to a cathode active material, and more particularly, to a cathode active material doped with a trivalent metal (Me) and a lithium secondary battery comprising the same. According to one aspect, there is provided the cathode active material doped with the trivalent metal (Me), represented by the formula Li x Mn 2 Me y O 4 (here, x is from 0.5 to 1.3, and y is from 0.01 to 0.1). According to the present disclosure, release of manganese ions of the cathode active material greatly reduces, and consequently, capacity and cycle life of the battery may be significantly improved.

First claim

What is claimed is:

1. A cathode for a lithium secondary battery, comprising:
a lithium manganese oxide-type cathode active material doped with a trivalent metal (Me), represented by the following chemical formula 1 and a nickel-manganese-cobalt ternary system cathode active material represented by the following chemical formula 2:
Li x Mn 2 Me y O 4   [Chemical formula 1]

where x is from 0.5 to 1.3, and y is from 0.01 to 0.1,
Li a Ni 1-z-w Mn z Co w O b   [Chemical formula 2]

where a is from 0.95 to 1.1, z is from 0.1 to 0.9, w is 0.1 to 0.9, and b is from 1 to 2,
wherein the trivalent metal (Me) is one selected from the group consisting of Al, Co, Cr, Fe, Ni, Mg, and Ti,
wherein a content ratio of the lithium manganese oxide-type cathode active material represented by the above chemical formula 1 and the nickel-manganese-cobalt ternary system cathode active material represented by the above chemical formula 2 is from 1:9 to 9:1 based on a weight ratio.

2. The cathode for the lithium secondary battery according to claim 1 , wherein the trivalent metal (Me) is Al or Co.

3. The cathode for the lithium secondary battery according to claim 1 , wherein the lithium manganese oxide-type cathode active material is in a form of particles having an average diameter of 20 μm to 25 μm.

4. The cathode for the lithium secondary battery according to claim 1 , wherein the cathode further comprises a binder, and a conductive material.

5. A lithium secondary battery comprising:
a cathode;
an anode; and
a separator interposed between the cathode and the anode,
wherein the cathode is defined in claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Lee Yong-Seok
• Ryu Duk-Hyun
• Kim Jung-Jin

Classifications

• C01G51/54

  of the type (Mn2O4)-, e.g. Li(CoxMn2-x)O4 or Li(MyCoxMn2-x-y)O4 · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01P2002/32

  spinel-type (AB2O4) · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/505

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