| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery in which degradation in performance due to oxidative decomposition of a nonaqueous electrolyte hardly occurs, and which is excellent in a cycle life. <P>SOLUTION: The lithium ion secondary battery includes: a positive electrode which has a positive electrode active material which expresses a potential of at least 4.5 V by a metallic lithium reference; a negative electrode; and a nonaqueous electrolyte in which a lithium salt is dissolved in a nonaqueous solvent, wherein the nonaqueous solvent contains a cyclic carbonate and a chain-like carbonate as a principal component, and boron ethoxide is added to the nonaqueous electrolyte. <P>COPYRIGHT: (C)2011,JPO&INPIT |
