| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery which has excellent charge/discharge cycle characteristics and improved safety at high-rate charging by disposing two kinds of separators with different permeabilities of lithium ion. <P>SOLUTION: The nonaqueous electrolyte secondary battery is provided with a spiral electrode group in which a belt-like negative electrode 11 and a belt-like positive electrode 12 are spirally wound facing each other via belt-like separators 13, 14 interposed therebetween. The belt-like separators 13, 14 consist of a first separator 13 disposed in contact with the outer peripheral surface of the belt-like negative electrode 11 and a second separator 14 disposed in contact with the inner peripheral surface of the belt-like negative electrode 11, a permeability of lithium ion of the first separator 13 being smaller than that of the second separator 14. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
