ELECTRODE MIXTURE PASTE FOR SODIUM SECONDARY CELL, POSITIVE ELECTRODE FOR SODIUM SECONDARY CELL, AND SODIUM SECONDARY CELL
An electrode mixture paste for a sodium secondary battery contains a positive electrode active material capable of being doped and dedoped with a sodium ion, an electroconductive material, a binder, an organic solvent and an acid having a valence number of 2 or more. The electrode mixture paste for a sodium secondary battery gives little change in viscosity with lapse of time even when there are no special facilities.
1 . An electrode mixture paste for a sodium secondary battery, containing a positive electrode active material that is doped and undoped with a sodium ion, an electroconductive material, a binder, an organic solvent, and an acid having a valence number of 2 or more.
2 . The electrode mixture paste for a sodium secondary battery according to claim 1 , wherein said acid having a valence number of 2 or more is an organic acid.
3 . The electrode mixture paste for a sodium secondary battery according to claim 2 , wherein said organic acid is oxalic acid, malic acid, or succinic acid.
4 . The electrode mixture paste for a sodium secondary battery according to claim 1 , wherein said acid having a valence number of 2 or more is an inorganic acid.
5 . The electrode mixture paste for a sodium secondary battery according to claim 4 , wherein said inorganic acid is phosphoric acid, boric acid, or sulfuric acid.
6 . A positive electrode for a sodium secondary battery which is formed by applying an electrode mixture paste for a sodium secondary battery according to claim 1 onto a current collector and drying the resultant.
7 . A sodium secondary battery comprising a positive electrode for a sodium secondary battery according to claim 6 , a negative electrode containing a negative electrode active material that is doped and undoped with a sodium ion, and an electrolyte.