Method of producing anode material for non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-8945445-B2
Application number	US-201113188008-A
Country	US
Kind code	B2
Filing date	Jul 21, 2011
Priority date	Jan 21, 2009
Publication date	Feb 3, 2015
Grant date	Feb 3, 2015

Abstract

Provided is a method of producing an anode material for a non-aqueous electrolyte secondary battery having battery characteristics equivalent to those of a conventional product by simpler production steps than those of a conventional method.
A thermally-polymerized petroleum based or coal based pitch is cooled to the softening point or below so that the pitch is solidified to obtain a solidified pitch. The solidified pitch is ground to form a fine pitch powder having an average particle size (median size) of 60 μm or smaller. Then, the fine pitch powder is compression molded at a pressure of 20 to 100 MPa or 0.1 to 6 MN/m to form a porous compression molded pitch. The porous compression molded pitch is subjected to infusibilization treatment.

First claim

The invention claimed is:

1. A method of producing an anode material for a non-aqueous electrolyte secondary battery, comprising:
cooling a petroleum based or coal based pitch to a softening point or below so that the petroleum based or coal based pitch is solidified to obtain a solidified pitch without steps of blending by addition of an additive and extracting the additive with a solvent,
grinding the solidified pitch to form a fine pitch powder having a median size of 5 μm to 40 μm,
compression molding the fine pitch powder to form a porous compression molded pitch, and
subjecting the porous compression molded pitch to infusibilization treatment to obtain an infusibilized pitch having an oxygen content of 5 to 25 wt %.

2. The method of claim 1 , wherein the compression molding is conducted at a pressure of 20 to 100 MPa or 0.1 to 6 MN/m.

3. The method of claim 1 , further comprising classifying the fine pitch powder having a median size of less than 5 μm, melting at a softening point of the fine pitch powder or higher, and then cooling again to the softening point or below so that the fine pitch powder is solidified and reused as a solidified pitch.

4. The method of claim 3 , wherein the softening point is in the range of 140° C. to 260° C.

Assignees

• Komatsu Hajime
• Hara Kenjiro
• Miyahara Michihisa
• Kureha Corp

Inventors

• Komatsu Hajime
• Hara Kenjiro
• Miyahara Michihisa

Classifications

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• C04B2235/663

  Oxidative annealing · CPC title

• C04B2235/5427

  millimeter or submillimeter sized, i.e. larger than 0,1 mm · CPC title

• Y02T10/7011

  Cross-Sectional Technologies · mapped topic

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title