The PEO-(NH4)(2)SO4 systems with different NH4+/EO ratio have been prepared by the solution-cast technique and investigated by X-ray diffraction, infrared spectroscopy and impedance spectroscopy. The highest conductivity (2.7 x 10(-6) S cm(-1)) is obtained from the film with a NH4+/EO ratio of 0.050. Some electrochemical cells are then fabricated using the film with the highest electrical conductivity as the electrolyte. Different metal oxides and their combination are used as the cathode active materials. The highest open-circuit voltage (OCV) of 1.059 V is provided by the cell with configuration (Zn + ZnSO4. 7H(2)O)/PEO-(NH4)(2)SO4/(0.02 g PbO2 + 0.02 g MnO2). The short-circuit current of this cell is 97 mu A.