While solid oxide cells (SOCs) offer a promising technology for energy production and storage, their extensive commercialization faces challenges, primarily associated with high degradation rates. Although both fuel and oxygen electrodes are susceptible to distinct degradation mechanisms, substantial efforts have been dedicated to the comprehension of the underlying factors contributing to the diminished performance of the air electrodes. A proposed strategy to mitigate the degradation of these electrodes and increase their stability involves increasing the entropy of the material [1,2]. This research seeks to tackle the air electrode degradation challenge by investigating a perovskite material composed of high entropy oxide (HEO).

The material of choice in this work is a HEO material  which in the A-site of the perovskite structure contains several lanthanide group elements and with various transition metals (TM) occupying the B-site thus increasing the configurational entropy from 1.17R for LSCF to 2.94R for our HEO. The synthesis of this HEO material was accomplished using the Pechini method, a widely employed technique known for its effectiveness in producing finely powdered materials [3,4]. In this work, using the Pechini synthesis method, a single-phase perovskite structure of the high entropy oxide was obtained.

The synthesized HEO powder was then incorporated into a commercial anode-supported cell for comprehensive evaluation in both solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) environments. The ensuing results revealed a remarkable achievement – at 900 ^oC, a current density of 1.75 A·cm^-2 and 0.7 V was achieved. This performance stands out as one of the highest recorded current densities for a cell utilizing HEO materials.

Beyond the great performance, a key aspect of this HEO's performance lies in its exceptional stability over an extended period. Even when subjected to high current densities, such as 1 A·cm^-2, the material demonstrated remarkable stability, maintaining consistent behavior for more than 500 hours. This extended operational durability is a critical factor in advancing the practical application of HEO materials in solid oxide fuel cells, addressing one of the key challenges faced by the technology.

In conclusion, the integration of HEO  as air electrode into the SOC framework represents a significant leap forward in addressing the challenges hindering the widespread commercialization of solid oxide fuel cells. The high current density and prolonged stability observed in this research underscore the potential of HEO materials to redefine the landscape of SOC technology.