Enhanced Compatibility and Activity of High-entropy Double Perovskite Cathode Material for IT-SOFC

Intermediate-temperature solid oxide fuel cell (IT-SOFC) is promising for carbon neutrality, but its cathode is limited by the contradiction between thermal compatibility and catalytic activity.Herein, we propose a high-entropy double perovskite cathode material, GdBa(Fe 0.2 Mn 0.2 Co 0.2 Ni 0.2 Cu 0.2 ) 2 O 5+δ (HE-GBO) with improved compatibility and activity, in view of the high-entropy strategy by multi-elemental coupling, which possesses double perovskite structure and excellent chemical compatibility with state-of-the-art Gd 0.1 Ce 0.9 O 2-δ (GDC).The polarization resistance (R p ) of the symmetrical cells with HE-GBO cathode is 1.68 Ω•cm 2 at 800 ℃, and the corresponding R p of HE-GBO-GDC (mass ratio 7 : 3) composite cathode can be greatly reduced (0.23 Ω•cm 2 at 800 ℃) by introducing GDC.Dendritic microchannels anode-supported single cells with HE-GBO and HE-GBO-GDC cathodes realize maximum power densities of 972.12 and 1057.06 mW/cm 2 at 800 ℃, respectively, indicating that cell performance can be enhanced by high-entropy cathodes.The results demonstrate that high-entropy double perovskite cathode material HE-GBO has a high potantial to solve the conflict problem of thermal compatibility and catalytic activity in IT-SOFCs.