| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte for a lithium secondary battery having high fire retardancy and to provide the lithium secondary battery having high charge discharge cycle characteristics and high safety. <P>SOLUTION: The nonaqueous electrolyte for the lithium secondary battery using a nonaqueous solvent and a supporting salt and having a negative electrode using lithium or the lithium alloy contains a cyclic phosphazene compound represented by (NPR<SP>1</SP><SB>2</SB>)<SB>n</SB>in formula (I), [in the formula, R<SP>1</SP>independently represents a halogen element or a monovalent substituent group and n is 3-4.] and a fluorophosphate compound represented by formula (II), and the lithium secondary battery is equipped with the nonaqueous electrolyte, a positive electrode, and the negative electrode using lithium or its alloy. [In the formula, R<SP>2</SP>independently represents fluorine, an alkoxy group, or an aryloxy group, at least one of two R<SP>2</SP>s is the alkoxy group or the aryloxy group, and two R<SP>2</SP>s may form a ring by bonding each other.]. <P>COPYRIGHT: (C)2007,JPO&INPIT |
