SILICON BASED COMPOSITE MATERIAL, AND PREPARATION METHOD AND USE THEREOF

• US 20140295267A1
• Filed: 04/01/2014
• Published: 10/02/2014
• Est. Priority Date: 04/02/2013
• Status: Abandoned Application

• Current Assignee: Dongguan Amperex Technology Limited (TDK Corporation), Ningde Amperex Technology Limited (TDK Corporation)
• Original Assignee: Dongguan Amperex Technology Limited (TDK Corporation), Ningde Amperex Technology Limited (TDK Corporation)
• Inventors: WANG, Na
• Application Number:
  US14/242,773
• Publication Number:
  US 20140295267A1
• Time in Patent Office: Days
• US Class Current: 429/213
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/624 Electric conductive fillers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present disclosure provides a silicon based composite material, and a preparation method and a use thereof. The silicon based composite material comprises silicon nano-particles and polyaniline coating layers on surfaces of the silicon nano-particles, and Si—C covalent bonds are formed between the silicon nano-particles and the polyaniline coating layers. The silicon based composite material provided by the present disclosure is advantageous in improving the coating effect of polyaniline on silicon particles.

Claims

1. A silicon based composite material, comprising silicon nano-particles and polyaniline coating layers on surfaces of the silicon nano-particles, Si—

C covalent bonds being formed between the silicon nano-particles and the polyaniline coating layers.

2. The silicon based composite material according to claim 1, wherein an electric conductivity of the silicon based composite material is 1˜

6.5 S/cm.

3. The silicon based composite material according to claim 2, wherein the electric conductivity of the silicon based composite material is 1.98˜

4.63 S/cm.

4. The silicon based composite material according to claim 1, wherein a particle size D50 of the silicon nano-particles is 10˜

100 nm.

5. The silicon based composite material according to claim 1, wherein in the silicon based composite material, a weight ratio of the silicon nano-particles to the polyaniline coating layers is (45˜

85);

(55˜

15).

6. The silicon based composite material according to claim 1, wherein a hardness of the silicon based composite material is 1.4˜

3.5 GPa.

7. The silicon based composite material according to claim 6, wherein the hardness of the silicon based composite material is 2.6˜

3.5 GPa.

8. A preparation method of a silicon based composite material, comprising steps of:

conducting diazotization reaction under nitrite and an acidic condition by using p-phenylenediamine (H₂N—

Ar—

NH₂) to generate diazonium salt;

conducting substitution reaction by adding silicon nano-particles into a solution in which the diazotization reaction has achieved, to obtain a nano-silicon based precursor in which phenylamine monomers are linked to surfaces of the silicon nano-particles by Si—

C covalent bonds;

adding the nano-silicon based precursor into a microemulsion formed by mixing an oil phase with a water phase, adjusting pH of the microemulsion, and then adding phenylamine monomer;

conducting polymerization reaction of phenylamine by adding an initiator polymerizing phenylamine into the microemulsion, to obtain the silicon based composite material in which the surfaces of the silicon nano-particles are coated with polyaniline layers.

9. The preparation method of the silicon based composite material according to claim 8, wherein the nitrite is sodium nitrite, the acidic condition is provided by an organic acid or an inorganic acid.

10. The preparation method of the silicon based composite material according to claim 9, wherein the acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid and acetic acid.

11. The preparation method of the silicon based composite material according to claim 10, wherein the acid is hydrochloric acid, a mole ratio of p-phenylenediamine to sodium nitrite is 1:

(1.5˜

3), a mole ratio of p-phenylenediamine to hydrochloric acid is 1;

(2.7˜

5.4).

12. The preparation method of the silicon based composite material according to claim 8, wherein a mole ratio of the silicon nano-particles to p-phenylenediamine is 1:

(0.75˜

1.5) in the step of adding the silicon nano-particles into the solution in which diazotization reaction has achieved.

13. The preparation method of the silicon based composite material according to claim 8, wherein the oil phase employs cyclohexane and Tween-80, the water phase employs deionized water and ethanol.

14. The preparation method of the silicon based composite material according to claim 13, wherein a volume ratio of cyclohexane to Tween-80 is 9:

1;

a volume ratio of deionized water to ethanol is 1;

1;

a volume ratio of the water phase to the oil phase is 40;

100.

15. The preparation method of the silicon based composite material according to claim 8, wherein a ratio of a weight of the nano-silicon based precursor to a volume of the microemulsion is 18 g/L˜

28 g/L;

pH is adjusted to 1 with hydrochloric acid;

a weight ratio of the added phenylamine monomer to the nano-silicon based precursor is (1.25˜

2.5);

1.

16. The preparation method of the silicon based composite material according to claim 8, wherein the initiator contains ammonium persulfate, sodium dodecylbenzene sulfonate and hexadecyl trimethyl ammonium bromide.

17. The preparation method of the silicon based composite material according to claim 16, wherein a mole ratio of ammonium persulfate to sodium dodecylbenzene sulfonate to hexadecyl trimethyl ammonium bromide to the added phenylamine monomer is (0.1˜

0.4);

(0.01˜

0.04);

(0.01˜

0.04);

1.

18. The preparation method of the silicon based composite material according to claim 8, wherein the polymerization reaction is conducted at 10°

C.˜

25°

C.

19. The preparation method of the silicon based composite material according to claim 8, wherein an electric conductivity of the silicon based composite material is 1˜

6.5 S/cm.

20. A use of the silicon based composite material as a negative electrode active material for a lithium-ion battery, the silicon based composite material comprising silicon nano-particles and polyaniline coating layers on surfaces of the silicon nano-particles, Si—

C covalent bonds being formed between the silicon nano-particles and the polyaniline coating layers.