Abstract
As global energy demands shift toward a sustainable alternative, hydrogen-powdered solid oxide fuel cells (SOFCs) offer a high-efficiency, low-emission solution for electrical energy conversion. However, performance limitations at intermediate temperatures (600-800 °C) necessitate advancements in electrolyte and electrode design. The present work presents the fabrication of a trilayer (porous/dense/porous) La(0.8)Sr(0.2)Ga(0.8)Mg(0.2)O(3‑δ) electrolyte using a tape casting method, yielding a sintered structure with ∼55 μm thick, porous layers (∼55% porosity) and a ∼20 μm dense electrolyte supported by La(0.8)Sr(0.2)Ga(0.8)Mg(0.2)O(3‑δ) rings. The porous La(0.8)Sr(0.2)Ga(0.8)Mg(0.2)O(3‑δ) backbone is infiltrated with nominal chemical composition NdBaCoFeO(5+δ) (NBCF) and a Ni-Gd-doped-Ce (Ni-GDC) anode. Electrochemical impedance spectroscopy, distribution functions of relaxation times, and equivalent circuit modeling identified an optimal NBCF loading of 1.58 mg/cm(2), which minimizes charge transfer and diffusion resistance, reducing the area-specific resistance to 0.025 Ω cm(2) at 800 °C. Full cell testing under SOFC conditions achieves a peak powder density of 400 mW/cm(2) at 750 °C with low ohmic (0.11 Ω cm(2)) and polarization (0.33 Ω cm(2)) resistances.