Effect of Sr Doped La4Ni3O10±δ as a Cathode for IT-SOFC

Abstract

The effect of Sr doped La4-xSrxNi3O10±δ (x = 0, 0.05, 0.1, 0.2 and 0.3) has been investigated as an intermediate temperature SOFC cathode material. The Ruddlesden-Popper (RP) compositions of n = 3 were successfully synthesized via citrate gel method. The single phase of sintered La4-xSrxNi3O10±δ (x = 0, 0.05, 0.1 and 0.2) powders was confirmed as an orthorhombic structure. However, this structure changes to more symmetry with an increasing amount of Sr dopant. With x = 0.3, the phases of La1.7Sr0.3NiO4 as n = 1 RP and NiO appear without n = 3 RP. La3.95Sr0.05Ni3O10±δ shows the highest electrical conductivity with a value of 140 S/cm at room temperature. Nevertheless, the electrical conductivity of La4-xSrxNi3O10±δ decreases and further decreases with increasing amount of Sr. The conductivity values at 200°C of La4-xSrxNi3O10±δ (x =0, 0.05 and 0.1) are 89, 113 and 101 S/cm, respectively. For x = 0.3, the conductivity decreases lower than x 0.1 with its value of 36 S/cm because of the low conductivity phase of n = 1 RP.