Enhanced performance of Pr4Ni3O10±δ-Ce0.75Gd0.1Pr0.15O2−δ composite electrode via particle size grading

Abstract

A particle grading strategy was applied in Pr4Ni3O10±δ (PNO)–Ce0.75Gd0.1Pr0.15O2−δ (CGPO) composite electrodes for intermediate-temperature solid oxide fuel cells. By testing of ungraded and graded electrodes and analysis of the obtained impedance spectra with the help of the distribution of relaxation time, it was found that the increase in oxygen species diffusion resistance, due to greater tortuosity of electrode particles, can be suppressed by the grading strategy. At the same time, the step of charge transfer can be enhanced. Overall, graded electrodes have much lower area specific resistance (ASR) than ungraded electrodes. The lowest ASR obtained for graded electrodes is 0.059 Ω cm2 at 625 °C (0.025 Ω cm2 at 698 °C) and pO2 of 0.21 atm, nearly a one-fold decrease compared to 0.11 Ω cm2 for ungraded electrodes at the same condition.