A high performance La2NiO4+δ impregnated PrBaCo2O5+δ cathode for intermediate temperature solid oxide fuel cells

Three composite cathodes of La2NiO4+δ-PrBaCo2O5+δ (LNO-PBCO) are prepared by impregnating LNO into the PBCO skeleton. At different temperatures, the electrochemical performance of PBCO and composite cathodes was evaluated. Impregnating LNO into the PBCO skeleton twice significantly enhanced the cathode performance. Notably, the polarization resistance (Rp) value of the composite cathode reached 0.061 Ω cm2 at 750 ℃, marking an 58.78% reduction compared to PBCO (0.148 Ω cm2). Furthermore, at 750 ℃, the peak power density of single cell with the composite cathode is 28.73% higher than that of single cell with PBCO cathode. The distribution of relaxation times (DRT) analysis showed that LNO impregnation promoted the oxygen reduction reaction (ORR) in the low frequency region and the medium and high frequency regions, which were attributed to the increase of oxygen surface coefficient and active sites, respectively. Furthermore, the composite cathode addresses the drawback of insufficient LNO conductivity, meeting the requirements for cathode utilization.