Hollow La0.6Sr0.4Ni0.2Fe0.75Mo0.05O3-δ electrodes with exsolved FeNi3 in quasi-symmetrical solid oxide electrolysis cells for direct CO2 electrolysis

•Hollow LSNFM was prepared via a mild molten-salt-assisted method.•FeNi3 nanoparticles were exsolved from hollow LSNFM as electrocatalyst.•Quasi symmetrical cell was designed for pure CO2 electrolysis.•The current density increased by 40.5% compared to the symmetrical cell. Symmetrical solid oxide electrolysis cells (Sym-SOECs) have emerged as one of the most attractive cells for direct CO2 electrolysis owing to their structural advantages, low cost, and reversible operability. However, their practical applications are limited due to the non-availability of fuel electrode electrocatalysts with excellent performance. In this study, hollow La0.6Sr0.4Ni0.2Fe0.75Mo0.05O3-δ (LSNFM) electrodes were prepared via a mild molten-salt-assisted approach. Subsequently, quasi-Sym-SOECs were constructed using LSNFM electrodes, where the cathode exsolved FeNi3 nanoparticles to enhance CO2 reduction performance. Compared with Sym-SOECs, the proposed quasi-Sym-SOECs show improved current density of electrolysis and reduced interfacial polarization resistance, which demonstrate the advantages of quasi-Sym-SOECs for CO2 electrolysis.