| 摘要 |
PROBLEM TO BE SOLVED: To improve a cycle characteristic while maintaining a good storing characteristic, by containing a lithiumacetylacetonate derivative in a nonaqueous electrolyte. SOLUTION: A lithiumacetylacetonate derivative contained in a nonaqueous electrolyte is represented by a formula. In the formula, R1 and R2 are each alkyl group of carbon number 1-5 or fluorine atom substituted alkyl group. The amount adding to this compound is preferably 0.1-30 wt.% to the whole solvent of the electrolyte. As electrolyte salt contained in this electrolyte, LiPF6, LiBF4 or the like is preferable. Because the lithiumacetylacetonate derivative creates a stable and good quality coating on the surface of an negative electrode by using such electrolyte, contact between the negative electrode and an organic solvent molecule is broken to stabilize the organic solvent. As a result, a decomposition reaction of the electrolyte occurring during charge or discharge is restrained to prevent degradation of the electrolyte. |
