ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, METHOD FOR PRODUCING THE SAME, AND NEGATIVE ELECTRODE INCLUDING THE SAME

• US 20140127576A1
• Filed: 07/03/2012
• Published: 05/08/2014
• Est. Priority Date: 07/29/2011
• Status: Abandoned Application

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Yokoi, Mai, Minami, Hiroshi, Imachi, Naoki, Kato, Daisuke
• Application Number:
  US14/130,564
• Publication Number:
  US 20140127576A1
• Time in Patent Office: Days
• US Class Current: 429/213
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• 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 4/364 as mixtures
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/483 for non-aqueous cells H01M4/485 takes precedence
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: H01M 4/628 Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The invention provides an active material for nonaqueous electrolyte secondary batteries which contains a silicon oxide as an active material and can suppress the generation of gas during storage at high temperatures, a method for producing such active materials, a negative electrode for nonaqueous electrolyte secondary batteries including the active material, and a nonaqueous electrolyte secondary battery including the negative electrode. An active material for nonaqueous electrolyte secondary batteries is used which includes a silicon oxide having a surface coated with a polyacrylonitrile or a modified product thereof that has been heat treated.

Claims

1. An active material for nonaqueous electrolyte secondary batteries comprising a silicon oxide having a surface coated with a polyacrylonitrile or a modified product thereof, the polyacrylonitrile or the modified product thereof having been heat treated.

2. The active material for nonaqueous electrolyte secondary batteries according to claim 1, wherein the amount of coating with the polyacrylonitrile or the modified product thereof is in the range of 0.5 to 5.0 mass % relative to the total mass including the silicon oxide.

3. A method for producing the active material for nonaqueous electrolyte secondary batteries described in claim 1, comprising:

a step of coating the surface of the silicon oxide with the polyacrylonitrile or the modified product thereof; and

a step of heat treating the polyacrylonitrile or the modified product thereof covering the surface of the silicon oxide.

4. The method for producing the active material for nonaqueous electrolyte secondary batteries according to claim 3, wherein the temperature of the heat treatment is in the range of 130 to 400°

C.

5. A negative electrode for nonaqueous electrolyte secondary batteries, comprising the active material for nonaqueous electrolyte secondary batteries described in claim 1 and graphite as negative electrode active materials;

and a binder.

6. The negative electrode for nonaqueous electrolyte secondary batteries according to claim 5, wherein the binder includes carboxymethyl cellulose and styrene-butadiene latex.

7. The negative electrode for nonaqueous electrolyte secondary batteries according to claim 5, wherein the content of the active material for nonaqueous electrolyte secondary batteries is in the range of 1 to 100 mass % relative to the total mass including the graphite.

8. The negative electrode for nonaqueous electrolyte secondary batteries according to claim 5, wherein the content of the active material for nonaqueous electrolyte secondary batteries is in the range of 1 to 50 mass % relative to the total mass including the graphite.

9. A nonaqueous electrolyte secondary battery comprising the negative electrode described in claim 5, a positive electrode and a nonaqueous electrolyte.