Electrolyte materials in solid oxide fuel cells play a vital role in the performance of the cell. In the present work we are going to report a nano grained perovskite materials used for intermediate temperature (450–650 °C) solid oxide fuel cell. Here electrolytes having composition Ba_1−xSr_xCe_1−yZr_yO_3-δ where x = 0.2, 0.3 and y = 0.2, 0.3 were synthesized by sol-gel method. Two prepared samples were named as BSCZ1 and BSCZ2 for x = y = 0.2&0.3, respectively. Structural analysis and surface morphology were performed using XRD and SEM, respectively. The particle size of BSCZ1 and BSCZ2 electrolyte materials calculated by Scherer's formula were found to be 25 nm and 28 nm, respectively. The protonic conductivities were determined by four probe method and maximum results of measurements were found to be 0.007 and 0.008 S/cm for BSCZ1 and BSCZ2, respectively at temperature of 650 °C. Electrical impedance spectroscopy results show ionic behavior which is suited for good electrolytes. It has been noted that the BSCZ2 electrolyte material executes maximum power density of 250 mW/cm² at 650 °C.