POSITIVE-ELECTRODE ACTIVE MATERIAL FOR SECONDARY CELL, AND METHOD FOR MANUFACTURING SAME

The present invention provides a positive-electrode active material for a lithium-ion secondary cell or a sodium-ion secondary cell, which can effectively exhibit more excellent charge/discharge characteristics; and a method for manufacturing the positive-electrode active material. Namely, the present invention relates to a positive-electrode active material for a secondary cell comprising an oxide represented by formula (A): LiFeMnMPO, formula (B): LiFeMnMSiO, or formula (C): NaFeMnQPO; and carbon derived from a cellulose nanofiber supported thereon.