Composite cathode active material, cathode and lithium battery including the composite cathode active material, and method of preparing the composite cathode active material

Patent metadata

Field	Value
Publication number	US-2017194637-A1
Application number	US-201615181838-A
Country	US
Kind code	A1
Filing date	Jun 14, 2016
Priority date	Dec 31, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

A composite cathode active material includes: a first metal oxide including a plurality of layered crystalline phases comprising a first layered crystalline phase and a second layered crystalline phase, wherein the first and second layered crystalline phases have a different compositions than each other, and a second metal oxide different from the first metal oxide and including a composite crystalline phase, that is different from the first metal oxide, wherein the second metal oxide is represented by Formula 1, wherein at least a portion of the second metal oxide is disposed on a first layered crystalline phase of the plurality of layered crystalline phases of the first metal oxide, and wherein the first layer crystalline phase is in a space group of R-3m:
Li x M y O z   Formula 1
wherein, in Formula 1, 0≦x≦3, 1≦y≦3, and 2≦z≦8, and M is at least one selected from a Group 4 element to a Group 13 element.

First claim

What is claimed is:

1 . A composite cathode active material comprising:
a first metal oxide comprising a plurality of layered crystalline phases comprising a first layered crystalline phase and a second layered crystalline phase, wherein the first and second layered crystalline phases have a different compositions than each other; and a second metal oxide comprising a composite crystalline phase, wherein the composite crystalline phase is different from at least one of the plurality of layered crystalline phases of the first metal oxide, wherein the second metal oxide is represented by Formula 1, wherein at least a portion of the second metal oxide is disposed on a first layered crystalline phase of the plurality of layered crystalline phases of the first metal oxide, and wherein the first layered crystalline phase is in a space group of R-3m:
Li x M y O z   Formula 1

wherein, in Formula 1, 0≦x≦3, 1≦y≦3, and 2≦z≦8, and M is at least one selected from a Group 4 element to a Group 13 element.

2 . The composite cathode active material of claim 1 , wherein the second metal oxide comprising the composite crystalline phase is disposed on a surface of a particle of the composite cathode active material.

3 . The composite cathode active material of claim 2 , wherein the composite crystalline phase has a dimension of less than or equal to about 100 nanometers.

4 . The composite cathode active material of claim 1 , wherein the second metal oxide comprising the composite crystalline phase is disposed at a grain boundary of the first metal oxide and inside the composite cathode active material.

5 . The composite cathode active material of claim 1 , wherein the composite cathode active material comprises a pore within the composite cathode active material.

6 . The composite cathode active material of claim 5 , wherein each pore has a maximum diameter of about 500 nanometers.

7 . The composite cathode active material of claim 5 , wherein the second metal oxide comprising the composite crystalline phase is disposed in the pore.

8 . The composite cathode active material of claim 1 , wherein the composite cathode active material comprises lithium in an amount of less than or equal to about 3,000 parts per million.

9 . The composite cathode active material of claim 1 , wherein an amount of metal in the second metal oxide is in a range of about 0.01 mole percent to about 3 mole percent, based on a total amount of a metal in the first metal oxide.

10 . The composite cathode active material of claim 1 , wherein the first metal oxide is represented by Formula 2:
Li a Ni b Co c Mn d O 2   Formula 2
wherein, in Formula 2, 1.0≦a≦1.2, 0.7<b<1.0, 0<c<0.3, and 0<d<0.3.

11 . The composite cathode active material of claim 1 , wherein the plurality of layered crystalline phases of the first metal oxide comprises a second layered crystalline phase in a space group of C2/m.

12 . The composite cathode active material of claim 1 , wherein the plurality of layered crystalline phases of the first metal oxide comprises a second layered crystalline phase having a composition represented by Formula 3:
Li 2 MnO 3 .  Formula 3

13 . The composite cathode active material of claim 12 , wherein an amount of the second layered crystalline phase is greater than or equal to about 3 weight percent, based on a total weight of the composite cathode active material.

14 . The composite cathode active material of claim 1 , wherein the second metal oxide is represented by Formula 5:
Li x M′ y O z   Formula 5
wherein, in Formula 5, 0≦x≦3, 1≦y≦3, and 2≦z≦8, and M′ is at least one selected from manganese, vanadium, chromium, iron, cobalt, nickel, zirconium, rhenium, aluminum, boron, germanium, ruthenium, tin, titanium, niobium, molybdenum, and platinum.

15 . The composite cathode active material of claim 1 , wherein the second metal oxide is at least one selected from Li 3 VO 8 , V 2 O 5 , LiV 3 O 8 , LiMn 2 O 4 , Li 2 MnO 3 , LiNi 0.5 Mn 1.5 O 4 , LiCo 1-x Ma x O 2 where 0≦x<1 and Ma is a transition metal, LiNi 1-x Ma x O 2 where 0≦x<1 and Ma is a transition metal, and LiMn 1-x Ma x O 2 where 0≦x<1 and Ma is a transition metal.

16 . A cathode comprising a composite cathode active material of claim 1 .

17 . A lithium battery comprising the cathode of claim 16 .

18 . A method of preparing a composite cathode active material, the method comprising:
providing a first metal oxide comprising a plurality of layered crystalline phases, wherein each layered crystalline phase of the plurality of layered crystalline phases has a different composition than any other layered crystalline phase of the plurality of layered crystalline phases; combining the first metal oxide and a precursor of a second metal oxide to form a mixture, wherein the second metal oxide is represented by Formula 1; drying the mixture; and heat-treating the dried mixture to form the composite cathode active material:
Li x M y O z   Formula 1

wherein, in Formula 1, 0≦x≦3, 1≦y≦3, and 2≦z≦8, and M is at least one selected from a Group 4 element to a Group 13 element.

19 . The method of claim 18 , wherein the precursor of the second metal oxide comprises a material which does not comprise lithium.

20 . The method of claim 18 , wherein the drying or heat-treating of the mixture is performed in an oxygen atmosphere at a temperature in a range of about 200° C. to about 800° C. for about 2 hours to about 40 hours.

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Ahn Sungjin
• Yu Byongyong
• Song Jayhyok
• Kapylou Andrei
• Park Jinhwan

Classifications

• 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

• H01M4/505

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

• H01M4/364 Primary

  as mixtures · 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