Nonaqueous electrolyte composition, nonaqueous electrolyte secondary battery, and method for manufacturing nonaqueous electrolyte secondary battery

1. A method for manufacturing a nonaqueous electrolyte secondary battery comprising:

mixing a nonaqueous solvent, an electrolyte salt, a matrix polymer and a ceramic powder to form an electrolyte mixture, and

using the electrolyte mixture to form a nonaqueous electrolyte material having a contact portion that is in contact with an electrode surface portion of at least one of a cathode and an anode, the electrode surface portion also including the ceramic powder,

wherein the ceramic powder is selected from the group consisting of Al 2 O 3 , ZrO 2 , TiO 2 , MgO and mixtures thereof,

wherein the electrolyte mixture has a viscosity of 25 mPas to 70 mPas,

wherein a content of the matrix polymer ranges from about 4% by mass to about 15% by mass of the nonaqueous electrolyte material, and

wherein a concentration of the ceramic powder in the contact portion of the nonaqueous electrolyte material is greater than a concentration of the ceramic powder in the electrode surface portion.

2. The method according to claim 1 , wherein the electrolyte mixture has a viscosity of 40 to 70 mPas.

3. The method according to claim 1 , wherein the electrolyte mixture further includes a viscosity-adjusting solvent.

4. The method according to claim 1 , comprising:

mixing a viscosity-adjusting agent with the electrolyte mixture in an amount so as to achieve the viscosity of 25 mPas to 70 mPas.

5. The method according to claim 1 , wherein a content ratio of the ceramic powder to the matrix polymer is 1/1 to 5/1 by mass.

6. The method according to claim 1 , wherein the ceramic powder has an average particle size of 0.1 to 2.5 μm and a specific surface area of 0.5 to 11 m 2 /g.

7. The method according to claim 1 , wherein the matrix polymer is selected from the group consisting of: polyvinyl formal, polyacrylic ester, polyvinylidene fluoride, and a copolymer of polyvinylidene fluoride and at least one of hexafluoropropylene, chlorotrifluoroethylene and polytetrafluoroethylene.

8. The method according to claim 1 , wherein the nonaqueous electrolyte solvent comprises at least one selected from the group consisting of: ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, 4-fluoro-1,3-dioxolan-2-one, 4-chloro-1,3-dioxolan-2-one, trifluoromethylethylene carbonate, γ-butyrolactone and γ-valerolactone, N-methylpyrrolidone, N-methyloxazolidinone, tetramethylene sulfone, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, methyl propyl carbonate; methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethylacetate, ethyl trimethylacetate, N,N-dimethylacetamide, methyl N,N-diethylcarbamate, ethyl N,N-diethylcarbamate, 1,2-dimethoxyethane, tetrahydrofuran, tetrahydropyran, and 1,3-dioxolane.