P3 METHODE FOR PRODUCING SODIUM COMPOSITE TRANSITION METAL OXIDE POSITIVE ELECTRODE ACTIVE MATERIAL FOR SODIUM SECONDARY BATTERY POSITIVE ELECTRODE AND SODIUM SECONDARY BATTERY COMPRISING THE SAME

摘要

The present invention relates to a positive electrode active material for a sodium secondary battery, which comprises sodium composite transition metal oxide having a P3 crystal structure and represented by the following chemical formula 1, Na_x[Li_aM_(1-a)]O_2; and a positive electrode and a secondary battery comprising the same. In the chemical formula 1, M is a transition metal, and 0.64 = x = 0.7 and 0.01 = a = 0.1 are satisfied. When applied to a sodium secondary battery, excellent life characteristics can be realized.