Fabrication of Ni-YSZ anode supported tubular SOFC through iso-pressing and co-firing route

Abstract

In the present work, a co-pressing and co-firing process has been developed to fabricate thin YSZ electrolyte film over tubular NiO-YSZ anode support for solid oxide fuel cell (SOFC) application. The one-end-closed tubular anode support was fabricated by cold isostatic pressing (CIP) and electrolyte coating was made by dip coating a terpineol based YSZ slurry over the anode support. The anode support along with coated electrolyte layer was co-pressed in CIP and co-fired at 1350 °C to get impervious electrolyte layer. LSM-YSZ composite cathode layer and LSM cathode current collector layer was formed by dip coating terpineol based slurries followed by sintering at 1150 °C. Symmetric cells in planar configuration were fabricated and tested by electrochemical impedance spectroscopy (EIS) in order to determine area-specific resistance (ASR) for electrode polarization. An ASR value of 0.79 Ω cm2 was obtained for Ni-YSZ|YSZ interface at 900 °C in humidified H2. The ASR value was 0.55 Ω cm2 for LSM-YSZ|YSZ interface at 900 °C in air. Tubular single cell having ∼1 cm2 cathode current collecting area was generated and the cell was found to give a maximum of 62 mW cm−2 power density when tested at 900 °C. The interfacial microstructures and electrochemical test results illustrate the feasibility of fabrication of tubular anode supported SOFC by co-pressing and co-firing.