Characterization of Na-based phosphate as electrode materials for electrochemical cells

摘要

We report the electrochemical properties of submicron-sized particles of NaFePO_4. Two materials have been studied and characterized by XRD, SEM, EDX, EIS and Raman experiments: the maricite phase synthesized by hydrothermal method and the olivine phase obtained from delithiation of LiFePO_4. NaFePCU materials have an electrochemical activity in Na cell using NaPF6-EC-DEC electrolyte, but only in the heterosite phase, and the capacity is reduced already in the second cycle. The two-phase system at intermediate compositions has also been analyzed.