| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a battery having a high capacity and improved cycle characteristics, and to provide a negative electrode active material used for the battery. <P>SOLUTION: A negative electrode 22 contains a negative electrode active material that can react with lithium. The negative electrode active material contains tin, cobalt, and carbon as constituting elements. In this case, the content of the carbon is 9.9% by mass or higher and 29.7% by mass or smaller, and the ratio of the cobalt to the total of tin and cobalt is 30% by mass or higher and 70% by mass or smaller. And the crystal phase of the intermetallic compound of cobalt and tin measured by an X-ray small-angle scattering method is 10 nm or smaller, thus maintaining a high capacity and improving cycle characteristics. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
