Electrochemical heat source

Electrochemical heat sources, materials used to make electrochemical heat sources and methods of forming electrochemical heat sources are disclosed. The electrochemical heat sources includes at least two metallic agents capable of interacting electrochemically with one another, such as magnesium and iron or nickel. The metallic agents may be provided in a variety of forms, including a frozen melt, a bimetallic foil, wire of a first metal wrapped around strands of a different metal, and a mechanical alloy. The metallic agents may be in the form of a powder filling a straw, or small particles extruded with a binder or pressed to form a rod. The powder filled straw or rod may be placed in a heat chamber surrounded by tobacco in a smoking article. An electrolyte solution contacts the metallic agents in the heat chamber to initiate the electrochemical interaction, generating heat which in turn may be used to volatilize nicotine and flavor materials in the tobacco. The heat sources may also be used to heat foods or beverages, in hand warmers, and to heat equipment or materials.