| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery with an excellent discharge capacity, a heavy-current discharging property and a charging/discharging cycle property. <P>SOLUTION: This nonaqueous electrolyte secondary battery is provided with an electrode group 22 provided with a positive electrode 32 comprising a positive electrode current collector 25 and a positive electrode active material layer 24 and a negative electrode 33 comprising a negative electrode current collector 27 and a negative electrode active material layer 26 and a separator 23, a nonaqueous electrolyte impregnated in the electrode group 22 and comprising a nonaqueous solvent and lithium salt dissolved in the nonaqueous solvent, and a case material 21 housing the electrode group 22 and made of a sheet containing a resin layer and having a thickness of 0.5 mm or less. The porosity of the positive electrode active material layer 24 is low than the porosity of the negative electrode active material layer 26. The thickness of the positive electrode active material layer 24 is 10-60 μm, and the thickness of the negative electrode active material layer 26 is 10-65 μm. The nonaqueous solvent contains γ-butyrolactone which is 40-95 vol.% of the whole nonaqueous solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
