The resistivity was measured by sending a dc
current of 1 mA in the temperature range 100–300 K during the heating
process. The voltage wasmeasured using a Keithley 614 high impedance
electrometer. For the fabrication of a solid state sodium battery, a
plasticized polymer electrolyte, (PEO)6:NaPO3+70 wt.% PEG400 has been
utilized. The cationic transport number and conductivity of the
electrolyte is found to be 0.42 and 10−6 Scm−1 has been utilized