ZERO VALENT FE POWDERS FOR HEAT SOURCE IN THERMAL BATTERIES AND MAKING METHOD OF THE SAME

A method for preparing zero valent iron powder used for a heat source of a thermal battery is provided to store the thermal battery for a long period of time by forming an amorphous nano oxide membrane on the thermal battery. A method for preparing zero valent iron powder used for a heat source of a thermal battery comprises the steps of preparing a precursor solution by mixing metal salt with fuel, forming liquid droplet having high viscosity by stirring the precursor solution while applying heat to the precursor solution, forming oxidized steel powder by heating the liquid droplet, and heat treating the oxidized steel powder at a hydrogen atmosphere. A surface treatment process is performed relative to the oxidized steel powder after the heat treatment process.