| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a secondary battery for improving cycle characteristics while securing first-time charge and discharge characteristics. <P>SOLUTION: The secondary battery includes a positive electrode 21, a negative electrode 22, and an electrolyte, and the electrolyte is impregnated into a separator 23 arranged between the positive electrode 21 and the negative electrode 22. A solvent of the electrolyte includes organic acid and a sulfone compound which are combined with each other. The organic acid includes a section including an electron suction group such as carbonyl group (-C(=O)-) or sulfonyl group (-S(=O)<SB>2</SB>-) at its center, and is a compound having hydroxyl group (-OH) at both ends. The sulfone compound is a cyclic compound having disulfone acid anhydrous group (-(O=)<SB>2</SB>S-O-S(=O)<SB>2</SB>-) or carboxylic acid sulfonic acid anhydrous group (-(O=)<SB>2</SB>S-O-C(=O)-). Decomposition reaction of the electrolyte is restrained in charge and discharge in order to improve chemical stability of the electrolyte. <P>COPYRIGHT: (C)2010,JPO&INPIT |
