| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a battery cell in which a cycle characteristic and a storage characteristic in improved, and also to provide an electrolyte used for it. <P>SOLUTION: A negative electrode 22 has a negative electrode current collector 22A and a negative electrode active material layer 22B. The negative electrode active material layer 22B contains Si, Sn or their alloy, and is formed by a vapor phase method, a liquid phase method, or a sintering method, and is alloyed with the negative electrode current collector 22A in at least one part of interface with the negative electrode current collector 22A. An electrolytic solution is impregnated in a separator 23. The electrolytic solution contains a fluorine containing salt of group II element of Mg(PF<SB>6</SB>)<SB>2</SB>, Mg (BF<SB>4</SB>)<SB>2</SB>or Mg[N(CF<SB>3</SB>SO<SB>2</SB>)<SB>2</SB>]<SB>2</SB>or the like as an additive. An ion of the group II element generated by dissociating the fluorine containing salt of the group II element is adsorbed to the negative electrode 22, or reduced at charging at the negative electrode 22 and a coating is formed, and a side effect at the negative electrode 22 is suppressed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
