POSITIVE ELECTRODE ACTIVE MATERIAL FOR SODIUM SECONDARY BATTERY AND PRODUCTION METHOD THEREFOR, AND SODIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a high capacity sodium ion secondary battery capable of repeating charge and discharge stably.SOLUTION: A positive electrode active material for sodium secondary battery contains a sodium-containing multiple oxide having P2 type crystal structure, and represented by Na(LiM)O, where 0x1.0 and 0.12a0.5. The element M contains at least Mn and Ni, and in the powder X-ray diffraction of the sodium-containing multiple oxide using CuKα ray, no peak is observed in a range of 18°-25°.SELECTED DRAWING: Figure 2