| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a battery capable of enhancing cycle characteristics. <P>SOLUTION: The battery has a positive electrode 21, a negative electrode 22, an electrolyte, and a separator 23 interposed between the positive electrode 21 and the negative electrode 22, wherein the separator 23 is impregnated with the electrolyte. The negative electrode 22 has a negative electrode active material layer 22B on a negative current collector 22A, the negative electrode active material layer 22B contains a negative electrode active material containing silicon and has two or more pores. After charge or discharge, the volume of a pore group having a pore size of 3-200 nm per unit weight of silicon is ≤0.3 cm<SP>3</SP>/g, and a rate of change of the penetration amounts of mercury into two or more pores measured by a method of mercury penetration is distributed so as to show the peak in pore size of 200-15,000 nm. Even when the negative electrode active material is easily expanded or shrunken at high activity in charge discharge, the electrolyte is hard to be decomposed, and the negative electrode active material layer 22B is hardly peeled from the negative current collector 22A. <P>COPYRIGHT: (C)2009,JPO&INPIT |
