Synthesis, characterization, and electrochemical studies of chemically synthesized NaFePO4

NaFePO4 is a naturally occurring mineral known as maricite. This compound has not been well characterized or examined for its potential use in battery applications. In the present study, NaFePO4 has been synthesized via the Pechini process with the resulting sample being characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Electrochemical properties have been investigated for possible application as a cathode in sodium-ion batteries. Electrodes of these materials were tested in coin cells using LiPF6 as the electrolyte and lithium metal as the counter electrode. Constant current cycling, cyclic voltammetry, and in situ frequency response analyses were performed. The results obtained demonstrate constant capacity or progressive increase in capacity with the consistently low internal resistance exhibited over consecutive cycles indicating possible application as a lithium analog in Na-ion batteries.

► Chemical synthesis of NaFePO4.
► NaFePO4 exhibits highly stable capacity of ∼30 mAh g−1.
► Potential of this system for large scale electrical grid is demonstrated.