Keywords: maricite and olivine phases of NaNiPO4, gel-combustion, impedance spectroscopy
Summary:Maricite phase of sodium metal phosphate compounds show electrochemically inactive nature but Olivine phase compounds show higher capacity and longer cycle life in sodium ion battery. We have prepared Olivine and Maricite phase of NaNiPO4 by urea assisted Gel-Combustion process. Both Olivine and Maricite phases of NaNiPO4 are obtained by calcine the intermediate compound at 400 oC and 550 oC for 6 h respectively. Crystalline phase and structure of the nanocrystalline NaNiPO4 samples were confirmed from the analysis of the XRD, SEM and FTIR results respectively. XRD results show the formation of Olivine and Maricite phases of NaNiPO4 for the calcined intermediate compound at 400 oC and 550 oC for 6 h respectively. From SEM measurement, it confirms the formation of spherical shape nanoparticles. Electrical conductivity of NaNiPO4 was studied through impedance spectroscopy measurement. The observed electrical conductivity at room temperature for olivine phase of NaNiPO4 is 3.34x10-7 S cm-1 and maricite phase of NaNiPO4 is 8.86x10-8 S cm-1. The detailed synthesis, characterization and temperature dependent electrical conductivity and dielectric constant studies will be presented and discussed to find out the suitability of synthesized NaNiPO4 compound for Sodium-Ion Battery Applications.