A solid polymer electrolyte system based on poly(vinyl pyrrolidone) (PVP) complexed with sodium chlorite (NaClO3) salt has been prepared by a solution — cast technique. Several experimental techniques, such as composition-dependence conductvity, temperature-dependence conductivity in the temperature range of 303–398K and transport number measurements, have been employed to characterize this polymer electrolyte system. The conductivity of the (PVP+NaClO3) electrolyte is about 104 times larger than that of pure PVP at room temperature. Transport number measurements show that the charge transport is mainly due to ions. An electrochemical cell with the configuration Na/(PVP+NaClO3)/(I2+C+electrolyte) has been fabricated and its discharge characteristics studied. The open-circuit voltage and short-circuit current are 2.77V and 1.35mA, respectively. A number of other cell parameters are reported.