| 摘要 |
[Problem] To provide a means with which it is possible to improve the cycle durability of an electrical device such as a lithium-ion secondary cell. [Solution] The present invention pertains to a negative-electrode active material for an electrical device. This negative-electrode active material for an electrical device comprises a silicon-containing alloy having a structure in which silicide phases containing a silicide of a transition metal are dispersed in a mother phase having amorphous or low-crystallinity silicon as the main component. The silicon-containing alloy has a composition represented by the following chemical formula (1): (in chemical formula (1): A is an unavoidable impurity; M is one or more transition metal elements; and x, y, z, and a represent mass% values, where 0 < x < 100, 0 < y < 100, 0 < z < 100, 0 ≤ a < 0.5, and x + y + z + a = 100). This invention is characterized in that silicide phases having an aspect ratio of at least 3 represent at least 2% of the total number of silicide phases. |
