CATHODE ACTIVE MATERIAL AND LITHIUM SECONDARY BATTERY CONTAINING THE SAME

• US 20130330612A1
• Filed: 08/12/2013
• Published: 12/12/2013
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: CHOI, Sang Kyu, LEE, SeungByung
• Granted Patent: US 9,246,162 B2
• Time in Patent Office: Days
• US Class Current: 429/211
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: C01G 45/1228 of the type [MnO2]n- , e.g. LiMnO2, Li[MxMn1-x]O2
• CPC Class Codes: C01G 45/1242 of the type [Mn2O4]-, e.g. LiMn2O4, Li[MxMn2-x]O4
• CPC Class Codes: C01G 51/50 of the type [MnO2]n- , e.g. Li(CoxMn1-x)O2, Li(MyCoxMn1-x-y)O2
• CPC Class Codes: C01G 53/50 of the type [MnO2]n- , e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
• CPC Class Codes: C01P 2002/32 spinel-type (AB2O4)
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Disclosed herein is a cathode active material for secondary batteries and a secondary battery including the same, the cathode active material including lithium manganese oxide (A) having a spinel crystal structure and at least two types of lithium nickel-manganese-cobalt composite oxides (B) containing Ni, Mn, and Co as transition metals, wherein the lithium nickel-manganese-cobalt composite oxides (B) are different from each other in terms of at least one selected from the group consisting of elemental composition, particle diameter, and density.

Claims

1. A cathode active material for secondary batteries, the cathode active material comprising lithium manganese oxide (A) having a spinel crystal structure and at least two types of lithium nickel-manganese-cobalt composite oxides (B) containing Ni, Mn, and Co as transition metals,

wherein the lithium nickel-manganese-cobalt composite oxides (B) are different from each other in terms of at least one selected from the group consisting of elemental composition, particle diameter, and density.

2. The cathode active material according to claim 1, wherein a mixture ratio of the lithium manganese oxide (A) to the lithium nickel-manganese-cobalt composite oxides (B) ranges from 30:

70 to 90;

10 by weight.

3. The cathode active material according to claim 1, wherein the lithium manganese oxide has a spinel crystal structure and has an elemental composition represented by Formula (1):

Li_1+xMn_2-yM_yO₄ 

 

(1)

where 0≦

x≦

0.2 and 0≦

y≦

1, and

M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W and Bi.

4. The cathode active material according to claim 1, wherein the lithium nickel-manganese-cobalt composite oxides are selected from compounds having an elemental composition represented by Formula (2):

Li_1+zNi_aMn_bCo_1-(a+b)O₂ 

 

(2)

where 0≦

z≦

0.1, 0.2≦

a≦

0.7, 0.2≦

b≦

0.7 and a+b≦

1.

5. The cathode active material according to claim 1, wherein the lithium nickel-manganese-cobalt composite oxides (B) comprise two types of oxides having the same elemental composition and different particle diameters.

6. The cathode active material according to claim 1, wherein the lithium nickel-manganese-cobalt composite oxides (B) comprise two types of oxides having the same particle diameter and different elemental compositions.

7. The cathode active material according to claim 5, wherein the lithium nickel-manganese-cobalt composite oxides (B) have an elemental composition of Li_1+zNi_1/3Mn_1/3Co_1/3O₂ (where 0≦

z≦

0.1) or Li_1+z1Ni_aMn_bCo_1-(a+b)O₂ (where 0≦

z1≦

0.1, 0.4≦

a≦

0.7, 0.2≦

b≦

0.4 and a+b≦

1).

8. The cathode active material according to claim 5, wherein the lithium nickel-manganese-cobalt composite oxides (B) comprising a first oxide (B1) and a second oxide (B2) have an average particle diameter in a range from 3 to 10 μ

m and an average particle diameter of the first oxide (B1) is 10 to 70% of an average particle diameter of the second oxide (B2).

9. The cathode active material according to claim 6, wherein the lithium nickel-manganese-cobalt composite oxides (B) have different elemental compositions selected from Li_1+zNi_1/3Mn_1/3Co_1/3O₂ (where 0≦

z≦

0.1) and Li_1+z1Ni_aMn_bCo_1-(a+b)O₂ (where 0≦

z1≦

0.1, 0.4≦

a≦

0.7, 0.2≦

b≦

0.4 and a+b≦

1).

10. The cathode active material according to claim 6, wherein, among the lithium nickel-manganese-cobalt composite oxides (B), a first oxide (B1) has an elemental composition of Li_1+zNi_1/3Mn_1/3Co_1/3O₂ (where 0≦

z≦

0.1) and a second oxide (B2) has an elemental composition of Li_1+z1Ni_aMn_bCo_1-(a+b)O₂ (where 0≦

z1≦

0.1, 0.4≦

a≦

0.7, 0.2≦

b≦

0.4 and a+b≦

1).

11. The cathode active material according to claim 6, wherein the lithium nickel-manganese-cobalt composite oxides (B) have an average particle diameter of 3 to 10 μ

m with an error of ±

10%.

12. The cathode active material according to claim 1, wherein the active material has an energy density of 150 to 220 Wh/kg.

13. A cathode mix comprising the cathode active material according to claim 1.

14. A cathode for secondary batteries, wherein the cathode mix according to claim 13 is applied to a current collector.

15. A lithium secondary battery comprising the cathode according to claim 14.

16. The lithium secondary battery according to claim 15, wherein the lithium secondary battery is used as a unit cell of a battery module that is a power source of a middle or large-scale device.

17. The lithium secondary battery according to claim 16, wherein the middle or large-scale device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or a power storage system.