Cathode active material and lithium secondary battery including the same, and method of manufacturing cathode active material

Patent metadata

Field	Value
Publication number	US-9905841-B2
Application number	US-201414907659-A
Country	US
Kind code	B2
Filing date	Aug 6, 2014
Priority date	Aug 22, 2013
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Disclosed are a cathode active material and a lithium secondary battery including the same, and a method of manufacturing the cathode active material, the method including:
(a) manufacturing a lithium metal oxide according to formula 1 below:

Li 1+z Ni a Mn b Co 1−(a+b) O 2   (1)
wherein 0≦z≦0.1, 0.1≦a≦0.8, 0.1≦b≦0.8 and a+b<1; (b) dry mixing the lithium metal oxide, and a precursor including zirconium and fluorine; and (c) changing the precursor including zirconium and fluorine into ZrO 2 and substituting some of oxygen (O) anions with F by heat-treatment after dry mixing of step (b), wherein the cathode active material is coated with ZrO 2 and F.

First claim

The invention claimed is:

1. A method of manufacturing a cathode active material for secondary batteries, the method comprising:
manufacturing a lithium metal oxide according to formula 1 below:
Li 1+z Ni a Mn b CO 1−(a+b) O 2   (1)

wherein 0≦z≦0.1, 0.1≦a≦0.8, 0.1≦b≦0.8 and a+b<1;
dry mixing the lithium metal oxide and a precursor comprising zirconium and fluorine; and
changing the precursor comprising zirconium and fluorine into ZrO 2 and substituting some of oxygen (O) anions with F, by heat-treatment after the dry mixing,
wherein the cathode active material is coated with ZrO 2 and F, and in the dry mixing, an amount of a lithium transition metal oxide mixed with the precursor is controlled such that a total amount of ZrO 2 and F coated on the lithium transition metal oxide is 0.001 to 0.100 wt % based on the total weight of the cathode active material.

2. The method according to claim 1 , wherein the lithium metal oxide of Formula 1 is Li 1 Ni 1/3 Mn 1/3 Co 1/3 O 2 or LiNi 0.5 Mn 0.3 Co 0.2 O 2 .

3. The method according to claim 1 , wherein the precursor comprising zirconium and fluorine is ZrF 4 .

4. The method according to claim 1 , wherein an amount of the mixed lithium transition metal oxide is controlled such that a total amount of ZrO 2 and F is 0.001 to 0.010 wt % based on a total weight of the cathode active material.

5. The method according to claim 1 , wherein the dry mixing is carried out by high energy milling.

6. The method according to claim 1 , wherein the heat-treating is carried out at 400 to 1000° C. for 4 to 7 hours.

7. A cathode active material for secondary batteries coated with ZrO 2 and F manufactured using the method according to claim 1 .

8. The cathode active material according to claim 7 , wherein ZrO 2 and F are coated to a thickness of 0.01 to 0.10 μm.

9. The cathode active material according to claim 7 , wherein an area coated with ZrO 2 and F is 60 to 100% based on a surface area of the cathode active material.

10. A cathode mix comprising the cathode active material according to claim 7 .

11. A cathode for secondary batteries comprising the cathode mix according to claim 10 coated on a collector.

12. A lithium secondary battery comprising the cathode for the secondary batteries according to claim 11 .

13. The lithium secondary battery according to 13 , wherein the lithium secondary battery is a unit cell of a battery module as a power supply of a medium and large-scale device.

14. The lithium secondary battery according to 14 , wherein the medium and large-scale device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a system for storing power.

Assignees

• Lg Chemical Ltd

Inventors

• Jin Joo Hong
• Lee Dae Jin
• Shin Sun Sik
• Kong Woo Yeon
• Jung Wang Mo

Classifications

• H01M4/366

  as layered products · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/1391

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

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title