# US 2014/0154564 A1 · Anode active material for lithium secondary battery, preparation method thereof, and lithium secondary battery comprising the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0154564 A1
- Document ID: US20140154564A1
- Status: Published application
- Kind: A1
- Application number: 14/168,138
- Filed: 2014-01-30
- Published: 2014-06-05
- Earliest claimed: 2012-11-30
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Jung Woo Yoo; Won Jong Kwon; Eui Yong Hwang; Kil Sun Lee; Je Young Kim; Yong Ju Lee
- Web page: https://patentgrep.com/patent/US20140154564A1

## CPC

- H01M 4/366: {as layered products}
- C30B 11/12: Vaporous components, e.g. vapour-liquid-solid-growth
- C30B 29/06: Silicon
- C30B 29/602: {Nanotubes}
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/587: for inserting or intercalating light metals
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis}
- H01M 4/13: Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- Y02E 60/10: Energy storage using batteries
- Y10S 977/762: Nanowire or quantum wire, i.e. axially elongated structure having two dimensions of 100 nm or less
- Y10S 977/948: Energy storage/generating using nanostructure, e.g. fuel cell, battery
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

Provided are an anode active material including carbon-based particles, silicon nanowires grown on the carbon-based particles, and a carbon coating layer on surfaces of the carbon-based particles and the silicon nanowires, and a method of preparing the anode active material. Since the anode active material of the present invention is used in a lithium secondary battery, physical bonding force between the carbon-based particles and the silicon nanowires may not only be increased but conductivity may also be improved. Thus, lifetime characteristics of the battery may be improved.

## Claims

### Claim 1

An anode active material comprising:
carbon-based particles;
silicon nanowires grown on the carbon-based particles; and
a carbon coating layer formed on surfaces of the carbon-based particles and the silicon nanowires.

### Claim 2 (depends on 1)

The anode active material of claim 1, wherein the carbon-based particles comprises any one selected from the group consisting of carbon-based powder, carbon black, natural graphite, and artificial graphite, or a mixture of two or more thereof.

### Claim 3 (depends on 1)

The anode active material of claim 1, wherein an average particle diameter (D50) of the carbon-based particles is in a range of 10 μm to 30 μm.

### Claim 4 (depends on 1)

The anode active material of claim 1, wherein a specific surface area (Brunauer-Emmett-Teller (BET)) of the carbon-based particles is in a range of 2.0 m2/g to 5.0 m2/g, and a compressed density of the carbon-based particles is in a range of 1.5 g/cc to 1.85 g/cc under a pressure of 12 mpa to 16 mpa.

### Claim 5 (depends on 1)

The anode active material of claim 1, wherein the silicon nanowire has a diameter ranging from 10 nm to 100 nm and a length ranging from 100 nm to 5 μm.

### Claim 6 (depends on 1)

The anode active material of claim 1, wherein an amount of silicon is in a range of 5 wt % to 30 wt % based on a total weight of the carbon-based particles on which the silicon nanowires are grown.

### Claim 7 (depends on 1)

The anode active material of claim 1, wherein a thickness of the carbon coating layer is in a range of 5 nm to 50 nm.

### Claim 8 (depends on 1)

The anode active material of claim 1, wherein the carbon coating layer covers the entire surfaces of the carbon-based particles and the silicon nanowires.

### Claim 9

A method of preparing an anode active material, the method comprising:
growing silicon nanowires on carbon-based particles by using a silicon raw material and a catalytic metal; and
forming a carbon coating layer on surfaces of the silicon nanowires and the carbon-based particles on which the silicon nanowires are grown.

### Claim 10 (depends on 9)

The method of claim 9, wherein the growing of the silicon nanowires is performed by a method selected from the group consisting of a vapor-liquid-solid (VLS) method, a solid-liquid-solid (SLS) method, a metal organic chemical vapor deposition (MOCVD) method, and a molecular beam epitaxy (MBE) method.

### Claim 11 (depends on 9)

The method of claim 9, wherein the silicon raw material comprises SiCl4, SiH4, or a mixture thereof.

### Claim 12 (depends on 9)

The method of claim 9, wherein the catalytic metal comprises any one selected from the group consisting of gold (Au), iron (Fe), silver (Ag), and nickel (Ni), or a mixed metal of two or more thereof.

### Claim 13 (depends on 9)

The method of claim 9, wherein the carbon coating layer is formed by coating the carbon-based particles on which the silicon nanowires are grown with a carbon precursor and performing a heat treatment.

### Claim 14 (depends on 13)

The method of claim 13, wherein the carbon precursor comprises gas including carbon or amorphous carbon.

### Claim 15 (depends on 13)

The method of claim 13, wherein the coating is performed by a dry or wet coating method using an amorphous carbon precursor, or a chemical vapor deposition (CVD) method using gas including carbon.

### Claim 16 (depends on 15)

The method of claim 15, wherein the wet coating method is performed by dipping the carbon-based particles on which the silicon nanowires are grown in an organic solvent in which amorphous carbon is diluted.

### Claim 17 (depends on 14)

The method of claim 14, wherein the amorphous carbon comprises any one selected from the group consisting of glucose, fructose, galactose, maltose, lactose, sucrose, a phenol-based resin, a naphthalene resin, a polyvinyl alcohol resin, an urethane resin, a polyimide resin, a furan resin, a cellulose resin, an epoxy resin, a polystyrene resin, a resorcinol-based resin, a phloroglucinol-based resin, a coal-derived pitch, a petroleum-derived pitch, and a tar, or a mixture of two or more thereof.

### Claim 18 (depends on 17)

The method of claim 17, wherein the amorphous carbon is a coal-derived pitch or a petroleum-derived pitch having a weight-average molecular weight ranging from 200 to 3,000.

### Claim 19 (depends on 13)

The method of claim 13, wherein a mixing ratio of the carbon-based particles on which the silicon nanowires are grown to the carbon precursor is in a range of 90 parts by weight:10 parts by weight to 99 parts by weight:1 part by weight.

### Claim 20 (depends on 16)

The method of claim 16, wherein the organic solvent comprises any one selected from the group consisting of ethanol, toluene, methanol, hexane, acetone, tetrahydrofuran, pyridine, quinoline, and benzoquinone, or a mixture of two or more thereof.

### Claim 21 (depends on 13)

The method of claim 13, wherein the heat treatment is performed at a temperature ranging from 300° C. to 1,500° C.

### Claim 22 (depends on 1)

An anode comprising a current collector, and the anode active material of claim 1 formed at least one surface of the current collector.

### Claim 23 (depends on 22)

A lithium secondary battery comprising a cathode, the anode of claim 22, and a separator disposed between the cathode and the anode.