A method of performing a high-temperature aging process of a rechargeable cell (10) comprising an anode (12), a cathode (16), an electrolyte (22) and a separator (20), is provided. The method includes heating a solid electrolyte interface (24) formed on the anode (12) to a predetermined temperature at which a saturated ionic conductivity of the solid electrolyte interface (24) is elevated, and holding the solid electrolyte interface (24) at the predetermined temperature for a predetermined minimum time at which ionic conductivity of the SEI becomes saturated.