Negative electrode active material for secondary battery and method for manufacturing same

• US 10,693,134 B2
• Filed: 07/02/2019
• Issued: 06/23/2020
• Est. Priority Date: 04/09/2014
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Cho, Young Tai, Park, Seung Chul, Park, Seon, Park, Jee Hye, Lee, Yong Eui, Kim, Chul Hwan, Seo, Hee Young
• Primary Examiner(s): McConnell, Wyatt P
• Application Number:
  US16/460,612
• Publication Number:
  US 20190326594A1
• Time in Patent Office: 357 Days
• Field of Search: None
• CPC Class Codes: C01B 33/113 Silicon oxides; Hydrates thereof preparing monoxide by reduction of siliceous material C01B33/182
• CPC Class Codes: C01B 33/18 Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C
• 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 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/049 Manufacturing of an active layer by chemical means
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1395 of 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 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/483 for non-aqueous cells H01M4/485 takes precedence
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Provided is an anode active material for a secondary battery and a method of fabricating the anode active material. A silicon-based active material composite according to an embodiment of the inventive concept includes silicon and silicon oxide obtained by oxidizing at least a part of the silicon, and an amount of oxygen with respect to a total weight of the silicon and the silicon oxide is restricted to 9 wt % to 20 wt %.

Claims

1. A secondary particle comprising agglomerated primary particles and a carbon-based conductive material for electrically connecting the agglomerated primary particles,

wherein an average diameter of the primary particles is 30 to 300 nm,

wherein each of the primary particles comprises a silicon core and a shell of silicon oxide surrounding the core, and

wherein the amount of oxygen in the primary particles with respect to the total weight of the silicon and the silicon oxide in the primary particles is 9 to 20 wt %.

2. The secondary particle of claim 1, wherein the average diameter of the primary particles is 30 to 200 nm.

3. The secondary particle of claim 1, wherein the shell of silicon oxide has a thickness of 2 to 30 nm.

4. The secondary particle of claim 1, wherein the shell of silicon oxide has a thickness of 3 to 15 nm.

5. The secondary particle of claim 1, wherein the amount of oxygen in the primary particles with respect to the total weight of the silicon and the silicon oxide in the primary particles is 10 to 20 wt %.

6. The secondary particle of claim 1, wherein the silicon oxide shell is formed on the silicon core of each of the primary particles by chemically oxidizing silicon particles by grinding a slurry of the silicon particles in a liquid solvent comprising oxygen.

7. The secondary particle of claim 1, wherein the carbon-based conductive material is formed by dispersing the primary particles in a solvent comprising a polymeric precursor of the carbon-based conductive material to obtain intermediate particles wet by the polymeric precursor, drying the intermediate particles, and heat treating to obtain the carbon-based conductive material.

8. The secondary particle of claim 1, wherein the carbon-based conductive material is formed of crystalline carbon, soft carbon, graphite, graphene, or amorphous carbon.

9. The secondary particle of claim 1, wherein the carbon-based conductive material has a greater mole fraction of sp² carbon than sp³ carbon.

10. The secondary particle of claim 1, wherein the carbon-based conductive material is a layer at the outermost portion of the primary particles.

11. The secondary particle of claim 10, wherein the carbon-based conductive material is formed of crystalline carbon, soft carbon, graphite, graphene, or amorphous carbon.

12. The secondary particle of claim 11, wherein the carbon-based conductive material has a greater mole fraction of sp² carbon than sp³ carbon.