Electrochemical evaluation of Ni-BaZr0.8Y0.1X0.1O3−δ (X=Co, Mn) perovskite anodes synthesized through spinach (green) and oxalic (chemical) assisted auto-combustion routes for IT-SOFCs

Abstract

The development of efficient and environmentally sustainable anode materials is essential for advancing solid oxide fuel cells (SOFCs). In this study, we introduced a pioneering green synthesis approach utilizing spinach leaves powder as a bio-derived chelating agent, alongside a conventional chemical route using oxalic acid, to synthesize Ni-BZr_0.8Y_0.1X_0.1O_3−δ (Ni-BZYX; X = Co, Mn) perovskite-based anodes. This eco-friendly method leverages natural, renewable spinach powder to reduce the environmental footprint of material synthesis, offering a sustainable alternative to traditional chemical processes. Structural characterization via XRD and FTIR confirmed the formation of single-phase cubic perovskite structures without secondary phases, demonstrating effective doping and phase stability in both synthesis routes. SEM analysis revealed that oxalic-acid-synthesized samples exhibited superior porosity, reduced particle agglomeration, and enhanced microstructural uniformity, facilitating efficient gas diffusion and expanding the electrochemically active triple-phase boundary (TPB). Electrochemical testing at 650 °C demonstrated that Ni-BZYCo (oxalic acid) delivered the highest power density of 0.56 W cm⁻². Although greenly synthesized anodes exhibited slightly lower performance due to minor residual impurities, the spinach-based approach represents a significant advancement toward sustainable SOFC materials with comparable structural and functional properties. This work underscores the environmental and practical potential of bio-derived synthesis strategies and positions Co-doped Ni-BZY as a high-performance anode for sustainable SOFC technologies.