Positive electrode active material for secondary battery and secondary battery including same

Patent metadata

Field	Value
Publication number	US-2017155133-A1
Application number	US-201615362139-A
Country	US
Kind code	A1
Filing date	Nov 28, 2016
Priority date	Nov 30, 2015
Publication date	Jun 1, 2017
Grant date	—

Abstract

A positive electrode active material for a secondary battery and a secondary battery including the same are provided. The positive electrode active material for a secondary battery includes on the surface of a core, a surface treatment layer composed of a B and Si-containing amorphous oxide, and thus may exhibit reduced moisture reactivity, improved thermal and chemical stability, and high-voltage stability.

First claim

What is claimed is:

1 . A positive electrode active material for a secondary battery, the positive electrode active material comprising:
a core including a lithium nickel manganese cobalt oxide; and a surface treatment layer positioned on the surface of the core, wherein the surface treatment layer includes a boron (B) and silicon (Si)-containing amorphous oxide.

2 . The positive electrode active material of claim 1 , wherein the surface treatment layer includes one or two or more selected from the group consisting of a borosilicate-based glass, an alkaliborosilicate-based glass, and an aluminoborosilicate-based glass.

3 . The positive electrode active material of claim 1 , wherein the surface treatment layer includes a borosilicate-based glass that includes B 2 O 3 and SiO 2 in a 50:50 to 80:20 weight ratio.

4 . The positive electrode active material of claim 1 , wherein the surface treatment layer includes an alkaliborosilicate-based glass that includes B 2 O 3 , SiO 2 , and R 2 O (where R is at least one alkali metal), and the alkaliborosilicate-based glass containing 1 to 20 parts by weight of R 2 O with respect to 100 parts by weight of the sum weight of B 2 O 3 and SiO 2 .

5 . The positive electrode active material of claim 1 , wherein the surface treatment layer includes an aluminoborosilicate-based glass that includes B 2 O 3 , SiO 2 , and Al 2 O 3 , and the aluminoborosilicate-based glass containing 0.1 to 10 parts by weight of Al 2 O 3 with respect to 100 parts by weight of the sum weight of B 2 O 3 and SiO 2 .

6 . The positive electrode active material of claim 1 , wherein the boron (B) and silicon (Si)-containing amorphous oxide glass in the surface treatment layer has a softening temperature of 1,100 to 1,300° C.

7 . The positive electrode active material of claim 1 , wherein the surface treatment layer is formed on at least 25% and less than 100% of the total surface area of the core.

8 . The positive electrode active material of claim 1 , wherein the surface treatment layer is formed to an average thickness ratio of 0.01 to 0.1 with respect to the radius of the core.

9 . The positive electrode active material of claim 1 , wherein the lithium nickel manganese cobalt oxide is doped with one or two or more elements selected from the group consisting of W, Mo, Zr, Ti, Mg, Ta, Al, Fe, V, Cr, Ba, Ca, and Nb.

10 . The positive electrode active material of claim 1 , wherein the core is a secondary particle assembled from primary particles.

11 . The positive electrode active material of claim 1 , wherein the core has an average particle diameter (D 50 ) of 1 to 20 μm.

12 . The positive electrode active material of claim 1 , wherein the BET specific surface area is 0.1 to 1.9 m 2 /g and the tap density is 1.5 to 3 g/cc.

13 . The positive electrode active material of claim 1 , wherein the positive electrode active material exhibits a lithium ion conductivity of at least 10 −7 S/cm at 25° C.

14 . A method for preparing the positive electrode active material for a secondary battery according to claim 1 , the method comprising:
a first operation for using a boron-containing raw material and a silicon-containing raw material to form a boron and silicon-containing amorphous oxide; and a second operation for mixing the amorphous oxide with a lithium nickel manganese cobalt oxide and then heat treating to form a surface treatment layer including the amorphous oxide on a core including the lithium nickel manganese cobalt oxide.

15 . The method of claim 14 , wherein the first operation is performed by mixing the boron-containing raw material with the silicon-containing raw material, melting at 1,000 to 1,800° C., and then cooling.

16 . The method of claim 14 , wherein the boron-containing raw material and the silicon-containing raw material are mixed in a 50:50 to 80:20 weight ratio.

17 . The method of claim 14 , wherein, in the first operation, a raw material including one or two or more elements selected from the group consisting of an alkali metal, aluminum, and a ceramic element is further added.

18 . The method of claim 14 , further comprising, following the first operation, an operation for milling the amorphous oxide to an average particle diameter of 100 to 500 nm.

19 . The method of claim 14 , wherein, in the second operation, the heat treatment is performed at a temperature of 300 to 600° C.

20 . A positive electrode for a secondary battery, the positive electrode comprising the positive electrode active material according to claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Lee Dae Jin
• Jung Wang Mo
• Park Sin Young

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/0471

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

• 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

• 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