A method of producing metallic sodium powders. The method includes immersing one or more solid pieces of sodium metal in an organic liquid containing a hydrocarbon oil. The solid piece(s) of sodium metal immersed in the hydrocarbon oil is (are) then subjected to ultrasonic irradiation, wherein the solid piece of sodium metal is fragmented to form sodium powder, resulting in a dispersion of the sodium powder in the organic liquid. The dispersed sodium powder is then separated from the organic liquid, resulting in metallic sodium powder. A method of presodiation of an anode in an electrochemical cell. The method includes adding sodium metal powders to the surface of the anode either as a dry powder or as a suspension of the sodium particles in an organic liquid. An anode in an electrochemical cell containing metallic sodium particles. An electrochemical cell comprising a presodiated anode.