| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide: a negative electrode active material suppressed in Si volume expansion; and a secondary battery arranged by use of such a negative electrode active material and having superior charge and discharge cycle characteristics.SOLUTION: A negative electrode active material comprises: a substantially amorphous Si alloy including 15-70 at% of Si, a total of 6-25 at% of at least one element M selected from Fe, Mn, Co, Cr, Ni and V, and 0.1-5.0 at% of an element X which exhibits a dissolution of 5 at% or less in each element of Si, the element M and Al at a crystallization temperature, and 10-75 at% of Al; and a Si-containing intermetallic compound of which the distribution density is 1×10to 1×10/mmin the substantially amorphous Si alloy.</p> |
