Significantly improving the performance of SrCo_0·8Nb_0·1Ta_0·1O_3-δ perovskite-based oxygen electrode on YSZ/Ni-supported YSZ|GDC solid oxide cells

Solid oxide cell (SOC) is an important device for efficient hydrogen-electric energy conversion. The development of high-performance oxygen electrode remains critical challenge for advancing SOC technology. SrCo_0.8Nb_0.1Ta_0.1O_3-δ (SCNT) oxygen electrode materials has been extensively investigated and successfully applied to the solid oxide fuel cell (SOFC) with Gd_xCe_1-xO_2-δ (GDCx) electrolyte. Nevertheless, the application of SCNT to the commercial SOC via the Yttria-stabilized Zirconia (YSZ) electrolyte results in an unfavorable interfacial reaction despite the presence of a GDCx interlayer, which significantly degrades the cell performance. Herein, we modified the SCNT-based electrode by introducing the conventional electrode material La_0·6Sr_0·4Co_0·2Fe_0·8O_3-δ (LSCF) to improve electronic conductivity and structure stability. A three-phase composite electrode material SCNT-LSCF-Gd_0.1Ce_0·9O_1.95 (SLG) was developed and well applied to SOC. This optimizing strategy effectively inhibits interfacial Sr diffusion between the SCNT and the YSZ, which significantly improves the fuel cell performance from 720 mW cm⁻² (SCNT) to 2170 mW cm⁻² (SLG) at 750 °C. Simultaneously, the SLG-based SOC exhibits a high electrolysis current density of 2530 mA cm⁻² at 750 °C (80 % H₂O–H₂ at 1.3 V).