Nonaqueous electrolyte and nonaqueous electrolyte secondary battery

A nonaqueous electrolyte comprising a nonaqueous solvent and a solute dissolved in said nonaqueous solvent, wherein:

• said nonaqueous solvent contains ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (BL), vinylene carbonate (VC), and a fifth component, which is a solvent other than said EC, PC, BL and VC;
• and
• the mixing ratio x (% by volume) of ethylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 15 and 50, i.e., 15≦x≦50, the mixing ratio y (% by volume) of propylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 2 and 35, i.e., 2≦y≦35, the mixing ratio z (% by volume) of γ-butyrolactone based on the total amount of the nonaqueous solvent falls within a range of between 30 and 85, i.e., 30≦z≦85, the mixing ratio w (% by volume) of vinylene carbonate based on the total amount of the nonaqueous solvent is larger than 0 and is not larger than 5, i.e., 0<w≦5, and the mixing ratio q (% by volume) of said fifth component based on the total amount of the nonaqueous solvent is larger than 0 and is not larger than 5, i.e., 0≦q≦5.

A nonaqueous electrolyte secondary battery, comprising a case having a wall thickness not larger than 0.3 mm, an electrode group provided in said case, and a nonaqueous electrolyte which is provided in said case and contains a nonaqueous solvent and a solute dissolved in said nonaqueous solvent, wherein:

• said nonaqueous solvent contains ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (BL), and a fourth component, which is a solvent other than said EC, PC and BL;
• and
• the mixing ratio x (% by volume) of ethylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 15 and 50, i.e., 15≦x≦50, the mixing ratio y (% by volume) of propylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 2 and 35, i.e., 2≦y≦35, the mixing ratio z (% by volume) of γ-butyrolactone based on the total amount of the nonaqueous solvent falls within a range of between 30 and 85, i.e., 30≦z≦85, and the mixing ratio p (% by volume) of said fourth component based on the total amount of the nonaqueous solvent is larger than 0 and is not larger than 5, i.e., 0≦p≦5.

A nonaqueous electrolyte secondary battery, comprising a case having a wall thickness not larger than 0.3 mm, an electrode group provided in said case, and a nonaqueous electrolyte which is provided in said case and contains a nonaqueous solvent and a solute dissolved in said nonaqueous solvent, wherein:

• said nonaqueous solvent contains ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (BL), vinylene carbonate (VC), and a fifth component, which is a solvent other than said EC, PC, BL and VC;
• and
• the mixing ratio x (% by volume) of ethylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 15 and 50, i.e., 15≦x≦50, the mixing ratio y (% by volume) of propylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 2 and 35, i.e., 2≦y≦35, the mixing ratio z (% by volume) of γ-butyrolactone based on the total amount of the nonaqueous solvent falls within a range of between 30 and 85, i.e., 30≦z≦85, the mixing ratio w (% by volume) of vinylene carbonate based on the total amount of the nonaqueous solvent is larger than 0 and is not larger than 5, i.e., 0≦w≦5, and the mixing ratio q (% by volume) of said fifth component based on the total amount of the nonaqueous solvent is larger than 0 and is not larger than 5, i.e., 0≦q≦5.

A nonaqueous electrolyte secondary battery, comprising a case having a wall thickness not larger than 0.3 mm, a positive electrode provided in said case, a negative electrode provided in said case, and an electrolyte layer arranged between said positive electrode and said negative electrode, and said electrolyte layer containing a nonaqueous electrolyte and a polymer for gelling the nonaqueous electrolyte, wherein:

• said nonaqueous solvent contains ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (BL) and a fourth component, which is a solvent other than said EC, PC and BL;
• and
• the mixing ratio x (% by volume) of ethylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 15 and 50, i.e., 15≦x≦50, the mixing ratio y (% by volume) of propylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 2 and 35, i.e., 2≦y≦35, the mixing ratio z (% by volume) of γ-butyrolactone based on the total amount of the nonaqueous solvent falls within a range of between 30 and 85, i.e., 30≦z≦85, and the mixing ratio p (% by volume) of said fourth component based on the total amount of the nonaqueous solvent is larger than 0 and is not larger than 5, i.e., 0≦p≦5.

A nonaqueous electrolyte secondary battery, comprising a case having a wall thickness not larger than 0.3 mm, a positive electrode provided in said case and capable of absorbing-desorbing lithium ions, a negative electrode provided in said case and capable of absorbing-desorbing lithium ions, a separator arranged between said positive electrode and said negative electrode, and a liquid nonaqueous electrolyte impregnated in at least said separator, and said liquid nonaqueous electrolyte containing a nonaqueous solvent and a solute dissolved in said nonaqueous solvent, wherein:

• said nonaqueous solvent contains ethylene carbonate, propylene carbonate, γ-butyrolactone and vinylene carbonate;
• and
• the mixing ratio x (% by volume) of ethylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 15 and 50, i.e., 15≦x≦50, the mixing ratio y (% by volume) of propylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 2 and 35, i.e., 2≦y≦35, the mixing ratio z (% by volume) of γ-butyrolactone based on the total amount of the nonaqueous solvent falls within a range of between 30 and 85, i.e., 30≦z≦85, and the mixing ratio w (% by volume) of vinylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 0.05 and 5, i.e., 0.05≦w≦5.

A nonaqueous electrolyte secondary battery, comprising a case having a wall thickness not larger than 0.3 mm, a positive electrode provided in said case and capable of absorbing-desorbing lithium ions, a negative electrode provided in said case and capable of absorbing-desorbing lithium ions, and an electrolyte layer arranged between said positive electrode and said negative electrode, and said electrolyte layer containing a nonaqueous solvent and a solute dissolved in said nonaqueous solvent, wherein:

• said nonaqueous solvent contains ethylene carbonate, propylene carbonate, γ-butyrolactone and vinylene carbonate;
• and
• the mixing ratio x (% by volume) of ethylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 15 and 50, i.e., 15≦x≦50, the mixing ratio y (% by volume) of propylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 2 and 35, i.e., 2≦y≦35, the mixing ratio z (% by volume) of γ-butyrolactone based on the total amount of the nonaqueous solvent falls within a range of between 30 and 85, i.e., 30≦z≦85, and the mixing ratio w (% by volume) of vinylene carbonate based on the total amount of the nonaqueous solvent falls within a range of between 0.05 and 5, i.e., 0.05≦w≦5.