Synthesis, structure and ionic conductivity of nanocrystalline Ce1−xLaxO2−δ as an electrolyte for intermediate temperature solid oxide fuel cells

•Ce1−xLaxO2−δ (x = 0 − 0.1) solid solutions showed linear increase in ionic conductivity with La3+•Ea is 1.49, 0.94, 0.87 and 0.70 eV for x = 0, 0.01, 0.03, 0.05 and 0.1 composition.•LDC showed highest ionic conductivity of 1.01 × 10−2 S cm−1 at 750 °C.•Electronic and ionic transference numbers are 0.20 and 0.80 at 700 °C for x = 0.1.•0.05 LDC showed the OCV of 0.81 V and max. power density of 41 mWcm−2.