A negative electrode active material having high cycle durability contains an alloy represented by the following chemical formula (1):
Si.sub.xSn.sub.yM.sub.zA.sub.a(1)
(in the chemical formula (1), M is at least one metal selected from the group consisting of Ti, Zn, C, and combinations thereof, A is unavoidable impurities, x, y, z, and a represent % by mass values, and in that case, 0<x<100, 0<y<100, 0<z<100, 0a<0.5, and x+y+z+a=100), in which the half width of the diffraction peak of the (111) surface of Si in the range of 2=24 to 33 by X ray diffraction measurement of the alloy using the CuK ray is 0.7 or more.

A negative electrode active material having high cycle durability contains an alloy represented by the following chemical formula (1):
Si.sub.xSn.sub.yM.sub.zA.sub.a(1)
(in the chemical formula (1), M is at least one metal selected from the group consisting of Ti, Zn, C, and combinations thereof, A is unavoidable impurities, x, y, z, and a represent % by mass values, and in that case, 0<x<100, 0<y<100, 0<z<100, 0a<0.5, and x+y+z+a=100), in which the half width of the diffraction peak of the (111) surface of Si in the range of 2=24 to 33 by X ray diffraction measurement of the alloy using the CuK ray is 0.7 or more.

A negative electrode for an electrical device includes: a current collector; and an electrode layer containing a negative electrode active material, an electrically-conductive auxiliary agent and a binder and formed on a surface of the current collector, wherein the negative electrode active material contains an alloy represented by a following formula (1): Si.sub.xZn.sub.yM.sub.zA.sub.a (in the formula (1) M is at least one metal selected from the group consisting of V, Sn, Al, C and combinations thereof, A is inevitable impurity, and x, y, z and a represent mass percent values and satisfy 0<x<100, 0<y<100, 0<z<100, 0a<0.5 and x+y+z+a=100), and elongation () of the electrode layer is 1.29<<1.70%.

A negative electrode for an electrical device includes: a current collector; and an electrode layer containing a negative electrode active material, an electrically-conductive auxiliary agent and a binder and formed on a surface of the current collector, wherein the negative electrode active material contains an alloy represented by a following formula (1): Si.sub.xZn.sub.yM.sub.zA.sub.a (in the formula (1) M is at least one metal selected from the group consisting of V, Sn, Al, C and combinations thereof, A is inevitable impurity, and x, y, z and a represent mass percent values and satisfy 0<x<100, 0<y<100, 0<z<100, 0a<0.5 and x+y+z+a=100), and elongation () of the electrode layer is 1.29<<1.70%.

Metallic matrix composites are synthesized by mixing a first reactant, a second reactant and a nucleator compound to obtain a reaction mixture, and heating the reaction mixture to an auto-activation temperature to initiate a self-propagating high-temperature synthesis reaction between the first and second reactants. The metallic matrix composite can include a metallic matrix and an in situ formed reinforcement. The reinforcement can be formed of discrete particles substantially uniformly dispersed within the metallic matrix. Each of the particles can have a reinforcement constituent disposed about a core formed of the nucleator compound.

Metallic matrix composites are synthesized by mixing a first reactant, a second reactant and a nucleator compound to obtain a reaction mixture, and heating the reaction mixture to an auto-activation temperature to initiate a self-propagating high-temperature synthesis reaction between the first and second reactants. The metallic matrix composite can include a metallic matrix and an in situ formed reinforcement. The reinforcement can be formed of discrete particles substantially uniformly dispersed within the metallic matrix. Each of the particles can have a reinforcement constituent disposed about a core formed of the nucleator compound.

In an electric device the negative electrode active material layer includes a silicide phase containing a silicide of a transition metal is dispersed in a parent phase containing amorphous or low crystalline silicon as a main component, a predetermined composition, and a ratio value (B/A) of a diffraction peak intensity B of a silicide of a transition metal in a range of 2=37 to 45 to a diffraction peak intensity A of a (111) plane of Si in a range of 2=24 to 33 in a predetermined range in an X-ray diffraction measurement using a CuK1 ray is used as a Si-containing alloy. A solid solution or an oxide-coated solid solution in which a coating layer containing an oxide in a predetermined amount is formed on the particle surface of the solid solution and is used in the positive electrode active material layer.

In an electric device the negative electrode active material layer includes a silicide phase containing a silicide of a transition metal is dispersed in a parent phase containing amorphous or low crystalline silicon as a main component, a predetermined composition, and a ratio value (B/A) of a diffraction peak intensity B of a silicide of a transition metal in a range of 2=37 to 45 to a diffraction peak intensity A of a (111) plane of Si in a range of 2=24 to 33 in a predetermined range in an X-ray diffraction measurement using a CuK1 ray is used as a Si-containing alloy. A solid solution or an oxide-coated solid solution in which a coating layer containing an oxide in a predetermined amount is formed on the particle surface of the solid solution and is used in the positive electrode active material layer.

The manufacturing method of a porous silicon material of the present disclosure includes a particle forming step of melting a raw material containing Al as a first element in an amount of 50% by mass or more and Si in an amount of 50% by mass or less to obtain a silicon alloy, a pore forming step of removing the first element from the silicon alloy to obtain a porous material, and a heat treatment step of heating the porous material to diffuse elements other than Si to a surface of the porous material.

The manufacturing method of a porous silicon material of the present disclosure includes a particle forming step of melting a raw material containing Al as a first element in an amount of 50% by mass or more and Si in an amount of 50% by mass or less to obtain a silicon alloy, a pore forming step of removing the first element from the silicon alloy to obtain a porous material, and a heat treatment step of heating the porous material to diffuse elements other than Si to a surface of the porous material.