INITIAL OPERATION METHOD FOR SODIUM-SULFUR BATTERY

PROBLEM TO BE SOLVED: To improve the subsequent operation of a battery by discharging it equally with smaller current as compared with a rated current so as to generate sodium polysulfide within a high resistance layer, and reducing the inner resistance of the battery. SOLUTION: In a sodium-sulfur battery, sodium ions reach an anode conducive material 14 through a solid electrolyte tube 12 and a high-resistance layer 15 from a cathode active material 13 at the time of discharge, and perform discharge, generating sodium sulfides. At the time of charge, the sodium sulfides dissociate, and sodium ions shift to a cathode chamber, and return to metallic sodium. At the time of initial operation, the initial discharge is performed until 0.5% of the full quantity of discharge electricity of the battery is discharged with current density of 0.01A/cm or under per surface area of the solid electrolyte tube 12. Hereby, the essential function of the battery is given by reducing the inner resistance of the battery gradually, and the subsequent operation of the battery can be improved.