| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a battery of which battery characteristics such as cycle characteristics can be improved. <P>SOLUTION: A negative electrode active material containing Sn or Si as a constituting element is contained in the negative electrode 22. An electrolytic solution is impregnated into a separator 23. In the electrolytic solution, 4-fluoro-1,3-dioxolane-2-on is contained. The amount of fluoride ions in the electrolytic solution is 10 wtppm or more and 500 wtppm or less, and the moisture content is 10 wtppm or less. By this, chemical stability of the electrolytic solution is improved, and according to charging and discharging, new coatings are sequentially formed on the surface of the negative electrode 22 by the fluoride ions contained in the electrolytic solution. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
