| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a secondary battery capable of enhancing cycle characteristics. <P>SOLUTION: The secondary battery includes a positive electrode 21, a negative electrode 22, and an electrolyte, and a separator 23 arranged between the positive electrode 21 and the negative electrode 22 is impregnated with the electrolyte. The negative electrode 22 has a negative electrode active material layer on a negative electrode current collector. The negative electrode active material layer contains at least one of silicon and a silicon compound as the negative electrode active material and a binder consisting of a polymer, and satisfies conditional expression (1) of 0.7≤B<A≤1.5, where, A is a ratio of the number of carbon atoms to the number of silicon atoms in the vicinity of the surface on the negative electrode current collector side in the negative electrode active material layer, and B is a ratio of the number of carbon atoms to the number of silicon atoms in the vicinity of the surface on the opposite side to the negative electrode current collector in the negative electrode active material layer. <P>COPYRIGHT: (C)2010,JPO&INPIT |
