MOLTEN-SALT BATTERY, CHARGE-DISCHARGE METHOD, AND CHARGE-DISCHARGE SYSTEM

摘要

A negative electrode including a positive electrode active material reversibly intercalating and deintercalating sodium, a negative electrode containing a negative active material reversibly intercalating and deintercalating sodium, a separator interposed therebetween, and a molten salt electrolyte, Comprises at least 90% by mass of an ionic liquid, wherein the ionic liquid comprises a primary salt and a secondary salt, the primary salt having a sodium ion and a primary anion, And a second anion, and the positive electrode active material comprises a composite oxide having a layered O3 type crystal structure containing Na, Fe and Co, wherein the amount of Co in the total of Fe and Co contained in the composite oxide is 40 atomic% to 60 atomic%.