Cathode active material for lithium secondary battery, cathode and lithium secondary battery comprising same, and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-11646409-B2
Application number	US-201916579031-A
Country	US
Kind code	B2
Filing date	Sep 23, 2019
Priority date	Dec 13, 2018
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

Provided are a cathode active material for a lithium secondary battery, a cathode and a lithium secondary battery each including the same, and a method of manufacturing the same. The cathode active material for a lithium secondary battery includes a core including a lithium metal oxide and a coating layer formed on a surface and the inner grain boundaries of the core, wherein the coating layer includes a metal sulfide.

First claim

What is claimed is:

1. A cathode active material for a lithium secondary battery comprising:
a core comprising a lithium metal oxide; and
a coating layer formed on a surface and inner grain boundaries of the core;
wherein the coating layer comprises a metal sulfide,
wherein the coating layer comprises the metal sulfide in an amount of 0.5 to 2 mol % based on the total mol number of the cathode active material,
wherein the metal sulfide comprises Cu,
wherein the lithium metal oxide comprises one or more selected from the group consisting of Li x Mn 1-y M′ y A 2 , Li x Mn 1-y M′ y O 2-z X z , Li x Mn 2 O 4-z X z , Li x Mn 2-y M′ y A 4 , Li x Co 1-y l M′ y A 2 , Li x Co 1-y M′ y O 2-z X z , Li x Ni 1-y M′ y A 2 , Li x Ni 1-y M′ y O 2-z X z , Li x Ni 1-y Co y O 2-z X z , Li x Ni 1-y-z Co y M′ z Aα, Li x Ni 1-y-z Co y M′ z O 2-α X α , Li x Ni 1-y-z Mn y M′ z A α , and Li x Ni 1-y -z Mn y M′ z O 2-α X 60 (where 0.95 ≤×≤1.1, 0≤y≤0.5, 0≤z≤0.5, and 0<α≤2),
wherein, M′ is at least one element selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Ru, Sn, Ti, As, Mo or a rare earth element, A is an element selected from the group consisting of O, F, S and P, and X is an element selected from the group consisting of F, S and P.

2. The cathode active material of claim 1 , wherein the cathode active material has a particle size of about 3 to 20 μm.

3. A lithium secondary battery, comprising:
a cathode comprising a cathode active material comprising i) a core comprising a lithium metal oxide and ii) a coating layer formed on a surface and inner boundaries of the core, wherein the coating layer comprises a metal sulfide;
wherein the coating layer comprises the metal sulfide in an amount of 0.5 to 2 mol % based on the total mol number of the cathode active material, wherein the metal sulfide comprises Cu;
an anode; and
an electrolyte,
wherein the lithium metal oxide comprises one or more selected from the group consisting of Li x Mn 1-y M′ y A 2 , Li x Mn 1-y M′ y O 2-z X z , Li x Mn 2 O 4-z X z , Li x Mn 2-y M′ y A 4 , Li x Co 1-y M′ y A 2 , Li x Co 1-y M′ y O 2-z X z , Li x Ni 1-y M′ y A 2 , Li x Ni 1-y M′ y O 2-z X z , Li x Ni 1-y Co y O 2-z X z , Li x Ni 1-y-z Co y M′ z A α , Li x Ni 1-y-z Co y M′ z O 2-α X α , Li x Ni 1-y-z Mn y M′ z A α , and Li x Ni 1-y-z Mn y M′ z O 2-α X α (where 0.95 ≤×≤1.1, 0≤y≤0.5, and 0<α2),
wherein, M′ is at least one element selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Ru, Sn, Ti, As, Mo or a rare earth element, A is an element selected from the group consisting of O, F, S and P, and X is an element selected from the group consisting of F, S and P.

4. A method of manufacturing a cathode active material for a lithium secondary battery of claim 1 , comprising:
preparing an admixture comprising the metal sulfide and the core comprising the lithium metal oxide; and
forming the coating layer on a surface and inner grain boundaries of the core by heating the admixture.

5. The method of claim 4 , wherein the admixture is prepared by dry mixing the metal sulfide and the core comprising the lithium metal oxide.

6. The method of claim 5 , wherein the dry mixing comprises at least one selected from the group consisting of a planetary ball mill method, a ball mill method, a hybridization method and a mechanofusion method.

7. The method of claim 4 , wherein the heating is performed at a temperature of about 350 to 450° C.

8. The method of claim 4 , wherein the admixture is formed to have a particle size of about 3 to 20 μm.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Oh Seung-Min
• Koh Kiseok
• Yeo Yeolmae
• Lee Yoon Sung
• Lee Jieun
• Kim Dongjun
• Park Sang Mok

Classifications

• H01M4/366 Primary

  as layered products · 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

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title