Ruddlesden-Popper phase materials for solid oxide fuel cell cathodes: A short review

In the last couple of decades, researchers have been working on Ruddlesden-Popper phases to realise them as components of solid oxide cells. Ruddlesden-Popper phase materials have been particularly proposed as materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). As such a sizeable literature was produced on Ruddlesden-Popper phases and in this short review we look at these studies with a particular focus on the structural chemistry, oxygen transport and electrical conductivity, electrochemical performance, and stability of these materials under operating conditions. More specifically, the materials have been studied for cathodes and, therefore, we believe a review dedicated to cathode applications of these materials will be beneficial for the community. A brief outlook on the future directions in the field will also be provided

La2Pr2Ni3O10±δ Ruddlesden-Popper phase as potential intermediate temperature-solid oxide fuel cell cathodes

Ruddlesden-Popper phases are layered oxides composed of nABO 3 perovskite layers sandwiched between two AO rock-salt layers. Herein a new composition of n = 3 Ruddlesden-Popper phases, La 2 Pr 2 Ni 3 O 10±δ , synthesised by the citrate sol-gel method is reported. A preliminary microstructure investigation combined with studies of the electrochemical performance of this new composition, La 2 Pr 2 Ni 3 O 10±δ as a potential cathode material in both symmetrical and single cell configurations is reported. The area specific resistance of the La 2 Pr 2 Ni 3 O 10±δ cathode was found to be 0.34 Ω cm 2 at 800 °C, which is significantly better than previous reports for the La 4 Ni 3 O 10±δ analogue under similar conditions. A modest peak power density of 0.19 W cm −2 at 800 °C was found, whilst electrode adhesion was identified as contributing to the modest performance