Method for crystallizing lithium transition metal oxide thin film by plasma treatment

• US 6,376,027 B1
• Filed: 10/17/2000
• Issued: 04/23/2002
• Est. Priority Date: 05/01/2000
• Status: Expired due to Fees

• Current Assignee: Korea Advanced Institute of Science and Technology
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: Lee, Ho, Park, Sung Chul, Lee, Jai Young, Kang, Yong Mook, Kang, Youn Seon
• Primary Examiner(s): CHEN, BRET P
• Application Number:
  US09/688,987
• Time in Patent Office: 553 Days
• Field of Search: 427/535, 427/539, 427/255.31, 427/126.3, 429/218, 429/209
• US Class Current: 427/535
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/58 After-treatment
• CPC Class Codes: C23C 14/5826 Treatment with charged particles C23C14/582 takes precedence
• CPC Class Codes: C23C 14/584 Non-reactive treatment
• CPC Class Codes: C23C 14/5853 Oxidation
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• 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 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for crystallizing a lithium transition metal oxide thin film for an electrode of a thin film-type lithium secondary battery is provided, in which the lithium transition metal oxide thin film is reacted with oxygen or argon plasma induced by a microwave or a radio frequency wave, thereby obtaining an excellent lithium transition metal oxide thin film in a degree of crystallization and electrochemical characteristics.

Claims

1. A method for crystallizing a lithium transition metal oxide thin film, the method comprising the steps of:

vapor-depositing a lithium transition metal oxide thin film as an electrode material on a substrate; and

subsequently treating the lithium transition metal oxide thin film by a plasma for a time period less than or equal to 20 minutes, the plasma including a gas selected from the group consisting of oxygen, an inert gas, or a mixture thereof.

2. The method as recited in claim 1, wherein the plasma treatment is performed using microwave or radio frequency energy.

3. The method as recited in claim 1, wherein the lithium transition metal oxide thin film is composed of at least one oxide selected from the group consisting of LiCoO₂, LiNiO₂, LiMn₂O₄, V₂O₂, V₆O₁₃, SnO₂, oxides of TiS₂, oxides of LiAl, LiGaO₂, LiTiO₂, and Li₃PO₄.

4. A method as recited in claim 1, wherein the plasma gas is oxygen, inert gas or a mixture of oxygen and inert gas.

5. The method as recited in claim 1, wherein the inert gas is any one selected from the group consisting of argon, helium, neon, krypton and xenon.

6. The method as recited in claim 1, wherein the substrate is any one type of substrate selected from the group consisting of a silicon substrate, an alumina substrate, a glass substrate and an aluminum substrate.

7. The method as recited in claim 1, wherein the substrate is a Pt/Ti/SiO₂/Si substrate in which a silicon substrate as a base is covered with silicon oxide (SiO₂), titanium (Ti) and platinum (Pt) in sequence.