Method of manufacturing nano-sized lithium-cobalt oxides by flame spraying pyrolysis

• US 6,902,745 B2
• Filed: 10/29/2002
• Issued: 06/07/2005
• Est. Priority Date: 06/03/2002
• Status: Expired due to Fees

• Current Assignee: Young Hoon Kwak
• Original Assignee: Korea Institute of Geoscience and Mineral Resources
• Inventors: Jang, Hee Dong, Kim, Do Su, Shon, Jung Soo, Lee, Churl Kyoung
• Primary Examiner(s): PAK, JOHN D
• Application Number:
  US10/282,022
• Publication Number:
  US 20030221589A1
• Time in Patent Office: 952 Days
• Field of Search: 424/489, 424/646, 423/141, 423/149, 423/179.5, 423/594.6, 429/231.95
• US Class Current: 424/489
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01G 51/42 containing alkali metals, e.g. LiCoO2
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: C01P 2002/82 by IR- or Raman-data
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for producing nano-sized lithium-cobalt oxide is provided by using flame-spray pyrolysis. The method comprises the steps of: spraying minute droplets, which is a solution dissolved lithium salt with cobalt salt at room temperature; atomizing the minute droplets through rapid expansion into a high temperature environment generated by combusting oxygen and hydrogen; decomposing and oxidizing the atomized minute droplets thermally at high temperature to produce nano-sized oxides in gaseous phase: and collecting the produced nano-sized composite oxides particles. The produced nano-sized lithium-cobalt oxide can be applied to a highly efficient lithium battery as the electrode materials and a thin film type of battery as well as to a miniaturized battery.

Claims

1. A method of producing nano-sized lithium-cobalt oxide by utilizing a flame spray pyrolysis, the method comprises the step of:

spraying minute droplets, which is a solution of dissolved lithium salt and cobalt salt at a temperature below 100°

C.,

atomizing the minute droplets by rapidly expanding into an environment of high temperature in the range of 800°

C. to 1700°

C. provided by combusting oxygen and hydrogen,

decomposing the atomized droplets thermally at said environment of high temperature in a few seconds to produce nano-sized oxides in gaseous phase, and

condensing and collecting the produced nano-sized lithium-cobalt oxides.

2. The method as claimed in claim 1, wherein said solution of dissolved lithium salt and cobalt salt has 1.2-2.0 mole ratio of lithium salt to cobalt salt.

3. The method as claimed in claim 2, wherein said lithium salt is selected from the group consisting of lithium acetate (LiCH₃COO), lithium nitrate (LiNO₃), lithium hydroxide (LiOH) and lithium carbonate (Li₂CO₃), and said cobalt salt is selected from the group consisting of cobalt acetate (Co(CH₃COO)₂), cobalt nitrate (Co(NO₃)₂), cobalt hydroxide (Co(OH)₂) and cobalt carbonate (CoCO₃).

4. The method as claimed in claim 1, wherein said minute droplets are produced by utilizing an ultrasonic generator disposed in a fluid reservoir.

5. The method as claimed in claim 1, wherein said high temperature is generated by a heat source which has five gas injection tubes, wherein the five gas injection tubes are arranged in sequential order starting from the center tube and moving outward, so that the center tube supplies said minute droplets and argon, and the remaining tubes in subsequent sequential order supply argon, hydrogen, oxygen plus air, and air.