Characteristics of poly(ethylene oxide) - NaI polymer electrolyte and electrochemical cell performances

Poly(ethylene oxide) (PEO)-NaI complexes with different sodium:oxygen ratios are prepared by the solution-casting method. The complex with Na+/O=0.022 gives the highest conductivity, viz., 5.21 X 10(-5) S cm(-1). X-ray diffraction studies studies show that the sample with the highest electrical conductivity exhibits the smallest coherent length. This complex is used as an electrolyte for the fabrication of (metal)/PEO-NaI/(metal oxide) electrochemical cells. The open-circuit voltage of the fabricated cell with the best performance is 407 mV. The short-circuit current is about 14 mu A.