Hollow silicon-based particle, preparation method thereof and anode active material for lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-9722242-B2
Application number	US-201414464802-A
Country	US
Kind code	B2
Filing date	Aug 21, 2014
Priority date	May 16, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A hollow silicon-based particle including silicon (Si) or silicon oxide (SiO x , 0<x<2) particle including a hollow core part therein, wherein a size of the hollow core part is from 5 nm to 45 μm, and a novel preparation method thereof are provided. Hollow is formed in the silicon-based particle, and volume expansion to the inward/outward of the silicon-based particle may be induced. Thus, the volume expansion of the silicon-based particle to the outward may be decreased, and the capacity properties and the life characteristics of a lithium secondary battery may be improved. According to the novel preparation method of the hollow silicon-based particle of the present invention, mass production is possible, producing rate is faster when compared to a common chemical vapor deposition (CVD) method or a vapor-liquid-solid (VLS) method, and the preparation method of the present invention is favorable when considering processes and safety.

First claim

What is claimed is:

1. A method for preparing hollow silicon-based particle, comprising the steps of:
i) preparing a polymer template;
ii) coating a surface of the polymer template with SiO 2 using a silicon-based precursor;
iii) obtaining hollow SiO 2 particle by removing the polymer template; and
iv) obtaining hollow silicon (Si) or silicon oxide (SiO x , 0<x<2) particle by reducing the hollow SiO 2 particle using an alkaline metal or an alkaline earth metal and acid treating the reduced product,
wherein the polymer template is a polyacrylonitrile-based polymer, and
wherein the poly acrylonitrile-based polymer is poly(acrylonitrile-[2-(methacryloyloxy)ethyl]trimethylammonium chloride) (P(AN-MTC)).

2. The method of claim 1 , wherein the removing of the polymer template in step iii) is conducted by heat treating at 300° C. to 1,400° C.

3. The method of claim 2 , wherein the removing of the polymer template in step iii) is conducted under an atmospheric environment.

4. The method of claim 2 , wherein the removing of the polymer template in step iii) is conducted under an inert atmosphere.

5. The method of claim 1 , further comprising a step of coating an outer wall of the hollow silicon (Si) or silicon oxide (SiO x , 0<x<2) particle with carbon by mixing the hollow silicon (Si) or silicon oxide (SiO x , 0<x<2) particle with a carbon precursor and heat treating after step iv).

6. The method of claim 5 , wherein the carbon precursor is pitch or a hydrocarbon-based material.

7. The method of claim 5 , wherein the heat treating is conducted at a temperature range of 300° C. to 1,400° C.

8. The method of claim 1 , wherein the P(AN-MTC) is prepared by an emulsion polymerization using acrylonitrile and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MTC) as monomers at 50° C. to 70° C.

9. The method of claim 1 , wherein the silicon-based precursor is an aromatic silicon alkoxide compound or a linear silicon alkoxide compound.

10. The method of claim 9 , wherein the aromatic silicon alkoxide compound includes at least one selected from the group consisting of phenyl triethoxysilane (PTES), phenyl trimethoxysilane (PTMS), diphenyl diethoxysilane (DDES) and diphenyl dimethoxysilane (DDMS).

11. The method of claim 9 , wherein the linear silicon alkoxide compound includes at least one selected from the group consisting of tetraethyl orthosilicate (TEOS), tetramethyl orthosilicate (TMOS), tetrapropyl orthosilicate (TPOS) and tetrabutyl orthosilicate (TBOS).

12. The method of claim 1 , wherein a ratio of the silicon-based precursor:polymer template is 1:1 to 19 by the weight.

13. The method of claim 1 , wherein the alkaline metal is lithium, sodium, potassium, rubidium, cesium or francium.

14. The method of claim 1 , wherein the alkaline earth metal is beryllium, magnesium, calcium, strontium, barium or radium.

Assignees

• Lg Chemical Ltd

Inventors

• Han Gi Beom
• Park Hong Kyu
• Jung Wang Mo
• Kang Sung Joong
• Jo Chi Ho
• Ryu Ji Hoon

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/366

  as layered products · CPC title