Heat-tolerant battery and charging/discharging method thereof

A heat tolerant battery provided with: a positive electrode that contains a positive electrode current collector and a positive electrode active material that is fixed to the positive electrode current collector, said positive electrode active material containing a sodium-containing transition metal compound capable of electrochemically storing and discharging sodium ion; a negative electrode that contains a negative electrode current collector and a negative electrode active material that is fixed to the negative electrode current collector, said negative electrode active material containing at least one member selected from the group consisting of a sodium-containing titanium compound and hardly graphitizable carbon that are capable of storing and discharging sodium ion at a lower potential than the sodium-containing transition metal compound ; and a sodium ion-conductive electrode that is at least interposed between the positive electrode and the negative electrode and contains a salt of an organic cation having a pyrrolidinium skeleton with a bis(perfluoroalkylsulfonyl)imide anion.