According to one implementation, a magnesium-lithium alloy contains not less than 10.50 mass % and not more than 16.00 mass % lithium, not less than 5.00 mass % and not more than 12.00 mass % aluminum, and not less than 2.00 mass % and not more than 8.00 mass % calcium. According to one implementation, a rolled stock is made of the above-mentioned magnesium-lithium alloy. According to one implementation, a processed product includes the above-mentioned magnesium-lithium alloy as a material.

According to one implementation, a magnesium-lithium alloy contains not less than 10.50 mass % and not more than 16.00 mass % lithium, not less than 5.00 mass % and not more than 12.00 mass % aluminum, and not less than 2.00 mass % and not more than 8.00 mass % calcium. According to one implementation, a rolled stock is made of the above-mentioned magnesium-lithium alloy. According to one implementation, a processed product includes the above-mentioned magnesium-lithium alloy as a material.

Provided is a novel production method for producing silicon clathrate II. In the production method for producing silicon clathrate II, in a reaction system in which a Na—Si alloy containing Na and Si and an Na getter agent coexist so as not to be in contact with each other, the Na—Si alloy is heated and Na evaporated from the Na—Si alloy is thus caused to react with the Na getter agent to reduce an amount of Na in the Na—Si alloy.

Provided is a novel production method for producing silicon clathrate II. In the production method for producing silicon clathrate II, in a reaction system in which a Na—Si alloy containing Na and Si and an Na getter agent coexist so as not to be in contact with each other, the Na—Si alloy is heated and Na evaporated from the Na—Si alloy is thus caused to react with the Na getter agent to reduce an amount of Na in the Na—Si alloy.

There is provided an electrode active material for a sodium secondary battery, containing Na and M.sup.1. Here, M.sup.1 is one or more elements selected from the group consisting of Si, Ge, Sn, Pb, Sb, and Bi, and a molar ratio (Na:M.sup.1) of Na to M.sup.1 is t:1, where t is a number of 2 or more and 3 or less.

Identifying a stable phase of a binary alloy comprising a solute element and a solvent element. In one example, at least two thermodynamic parameters associated with grain growth and phase separation of the binary alloy are determined, and the stable phase of the binary alloy is identified based on the first thermodynamic parameter and the second thermodynamic parameter, wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase. In different aspects, an enthalpy of mixing of the binary alloy may be calculated as a first thermodynamic parameter, and an enthalpy of segregation of the binary alloy may be calculated as a second thermodynamic parameter. In another example, a diagram delineating a plurality of regions respectively representing different stable phases of at least one binary alloy is employed, wherein respective regions of the plurality of regions are delineated by at least one boundary determined as a function of at least two thermodynamic parameters associated with grain growth and phase separation of the at least one binary alloy.

Identifying a stable phase of a binary alloy comprising a solute element and a solvent element. In one example, at least two thermodynamic parameters associated with grain growth and phase separation of the binary alloy are determined, and the stable phase of the binary alloy is identified based on the first thermodynamic parameter and the second thermodynamic parameter, wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase. In different aspects, an enthalpy of mixing of the binary alloy may be calculated as a first thermodynamic parameter, and an enthalpy of segregation of the binary alloy may be calculated as a second thermodynamic parameter. In another example, a diagram delineating a plurality of regions respectively representing different stable phases of at least one binary alloy is employed, wherein respective regions of the plurality of regions are delineated by at least one boundary determined as a function of at least two thermodynamic parameters associated with grain growth and phase separation of the at least one binary alloy.

A silicide-based alloy material and a device in which the silicide-based alloy material is used are disclosed. The silicide-based alloy material can reduce environmental impact and provide high thermoelectric FIGURE of merit at room temperature. Provided is a silicide-based alloy material comprising, as major components, silver, barium and silicon, wherein atomic ratios of elements that constitute the alloy material are as follows: 9 at %≤Ag/(Ag+Ba+Si)≤27 at %, 20 at %≤Ba/(Ag+Ba+Si)≤53 at %, and 37 at %≤Si/(Ag+Ba+Si)≤65 at %, where Ag represents a content of the silver, Ba represents a content of the barium and Si represents a content of the silicon, and the silicide-based alloy material has an average grain size of less than or equal to 20 μm.

A silicide-based alloy material and a device in which the silicide-based alloy material is used are disclosed. The silicide-based alloy material can reduce environmental impact and provide high thermoelectric FIGURE of merit at room temperature. Provided is a silicide-based alloy material comprising, as major components, silver, barium and silicon, wherein atomic ratios of elements that constitute the alloy material are as follows: 9 at %≤Ag/(Ag+Ba+Si)≤27 at %, 20 at %≤Ba/(Ag+Ba+Si)≤53 at %, and 37 at %≤Si/(Ag+Ba+Si)≤65 at %, where Ag represents a content of the silver, Ba represents a content of the barium and Si represents a content of the silicon, and the silicide-based alloy material has an average grain size of less than or equal to 20 μm.

An anode of a battery comprises lithium metal, and a dopant, in the lithium metal. The anode has a thickness of at most 50 μm, and the dopant is a metal with an electronegativity greater than lithium.