Effect of Mo-doping or Nd-deficient on NdBaCo2O5+δ as oxygen electrode material for IT-SOEC

The Intermediate-Temperature Solid Oxide Electrolysis Cells (IT-SOECs) is an efficient energy conversion and storage device utilized in the process of water electrolysis for hydrogen production. NdBaCo2O5+δ (NBC) double perovskite has garnered significant interest for its potential application in IT-SOECs. However, NBC required improved electrochemical performance at intermediate temperatures and a reduced thermal expansion coefficient (TEC). In this study, high-performance NdBaCo2-yMoyO5+δ (NBCMoy, y=0-0.07) and Nd1-xBaCo2O5+δ (Nd1-xBC, x=0-0.06) were synthesized through Mo-doping or Nd-deficient on NBC. Mo-doping and Nd-deficient increased the adsorbed oxygen (Oabs) concentration of NBC from 71.76% to 78.21% in NBCMo0.05 and 74.20% in Nd0.98BC, separately. Consequently, their electrochemical performance was improved. At 800 ℃, the polarization resistances of NBCMo0.05 and Nd0.98BC were 0.035 Ω·cm2 and 0.071 Ω·cm2, respectively, which were only 33% and 67% of the NBC. Furthermore, both materials exhibited a lower coefficient thermal expansion. NBCMo0.05 is a promising candidate for the oxygen electrode in IT-SOECs.