SILICON CARBON COMPOSITE CATHODE MATERIAL AND PREPARATION METHOD THEREOF, AND LITHIUM-ION BATTERY

• US 20150118567A1
• Filed: 12/31/2014
• Published: 04/30/2015
• Est. Priority Date: 08/28/2012
• Status: Abandoned Application

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Chen, Wei
• Application Number:
  US14/587,689
• Publication Number:
  US 20150118567A1
• Time in Patent Office: Days
• US Class Current: 429/231.8
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A silicon carbon composite cathode material includes a graphite particle, further includes a silicon or silicon-containing particle, and includes a porous carbon layer, where the silicon or silicon-containing particle is distributed in vicinity of the graphite particle, the porous carbon layer coats a surface of the graphite particle and the silicon or silicon-containing particle so as to combine the graphite particle and the silicon or silicon-containing particle together, the porous carbon layer is a low crystalline carbon layer or an amorphous carbon layer, an interlayer distance d(002) of the low crystalline carbon layer is ≧3.45 nm, and a size of the silicon or silicon-containing particle is smaller than a size of the graphite particle. The silicon carbon composite cathode material has a porous structure, a stable material structure, a high capacity, high conductivity performance, and good cycling performance.

Claims

1. A silicon carbon composite cathode material, comprising:

a graphite particle, a silicon or silicon-containing particle, and a porous carbon layer;

wherein the silicon or silicon-containing particle is distributed in vicinity of the graphite particle, the porous carbon layer coats a surface of the graphite particle and the silicon or silicon-containing particle so as to combine the graphite particle and the silicon or silicon-containing particle together, the porous carbon layer is a low crystalline carbon layer or an amorphous carbon layer, an interlayer distance d(002) of the low crystalline carbon layer is greater than or equal to 3.45 nm, and a size of the silicon or silicon-containing particle is smaller than a size of the graphite particle.

2. The silicon carbon composite cathode material according to claim 1, wherein:

the graphite particle is one or more of artificial graphite, natural graphite, and a mesocarbon microbead; and

the silicon-containing particle is a silicon-containing heterogeneous material, silicon alloy, or silicon oxide.

3. The silicon carbon composite cathode material according to claim 1, wherein a porous aperture of the porous carbon layer is 2-100 nm, and a thickness of the porous carbon layer is 0.03-5 μ

m.

4. The silicon carbon composite cathode material according to claim 1, wherein a particle diameter of the silicon or silicon-containing particle is 0.03-2 μ

m, and a particle diameter of the graphite particle is 1-40 μ

m.

5. The silicon carbon composite cathode material according to claim 1, wherein a weight percentage of silicon in the silicon carbon composite cathode material is 0.1-50%.

6. The silicon carbon composite cathode material according to claim 1, wherein a weight ratio of the silicon or silicon-containing particle, the graphite particle, and the porous carbon layer is 0.1-35:

35-99.8;

0.1-30.

10. A lithium-ion battery, comprising:

the silicon carbon composite cathode material according to claim 1.

7. A method for preparing a silicon carbon composite cathode material, the method comprising:

dissolving amphiphilic surfactant in a carbon precursor solution and stirring evenly to obtain a carbon precursor solution including surfactant;

obtaining a graphite particle and a silicon or silicon-containing particle, adding the particles into the carbon precursor solution including surfactant, stirring evenly, and drying the solution; and

heating the foregoing dried product at 900-1400°

C. under protection of an inert gas, so that a carbon precursor is carbonized and the surfactant is resolved to form a porous carbon layer and eventually obtain the silicon carbon composite cathode material of a porous structure.

8. The method for preparing a silicon carbon composite cathode material according to claim 7, wherein the surfactant is polyisoprene-b-poly(ethylene oxide), poly(ethylene glycol)-b-polyacrylonitrile, or (EO)_l-(PO)_m-(EO)_n, wherein 1, m, and n are 5-200.

9. The method for preparing a silicon carbon composite cathode material according to claim 7, wherein a mass ratio of the surfactant, the carbon precursor, the silicon or silicon-containing particle, and the graphite particle is 0.1-40:

0.1-40;

0.1-35;

35-99.8.