Anode active material for lithium secondary battery and preparation thereof

Patent metadata

Field	Value
Publication number	US-9972828-B2
Application number	US-201314041280-A
Country	US
Kind code	B2
Filing date	Sep 30, 2013
Priority date	Apr 5, 2011
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present invention relates to an anode active material for a lithium secondary battery, comprising a carbon material, and a coating layer formed on the surface of particles of the carbon material and having a plurality of Sn-based domains having an average diameter of 1 μm or less. The inventive anode active material having a Sn-based domains coating layer on the surface of a carbon material can surprisingly prevent stress due to volume expansion which generates by an alloy of Sn and lithium. Also, the inventive method for preparing an anode active material can easily control the thickness of the coating layer.

First claim

What is claimed is:

1. An anode active material for a lithium secondary battery, comprising:
a carbon material selected from the group consisting of spherical natural graphite, spherical artificial graphite and a mixture thereof; and
a coating layer consisting of a plurality of Sn-based domains having an average diameter of 1 μm or less,
wherein the coating layer is formed on the surface of particles of the carbon material;
the domains have a hemisphere shape and/or agglomeration of several hemispheres; and
the Sn-based domains are of an Sn alloy and wherein the Sn alloy is an alloy of Sn and a metal selected from the group consisting of Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Pd, Cd, Sb, Hg, and Bi,
the carbon material has an average particle size of 5 to 100 μm and
the coating layer is formed by electroplating using a pulse current and an electroplating electrolyte wherein the carbon material is dispersed in the electroplating electrolyte, and the coating layer has a density of 2.2 to 5.9 g·cm −3 .

2. The anode active material for a lithium secondary battery according to claim 1 , wherein the carbon material has a specific surface area of 10 m 2 /g or less.

3. An anode of a lithium secondary battery, comprising a current collector; and an anode active material layer formed on at least one surface of the current collector,
wherein the anode active material layer comprises the anode active material according to claim 1 .

4. A lithium secondary battery, comprising a cathode, an anode, and a separator interposed between the cathode and the anode,
wherein the anode is the anode according to claim 3 .

Assignees

• Lg Chemical Ltd

Inventors

• Woo Sang-Wook
• Kim Ki-Tae
• Kwon Yo-Han

Classifications

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title

• H01M4/366

  as layered products · CPC title