Contact Formation at Interface of LSCO|BCZY|LSCO Symmetrical Cell: Effect of LSCO to PVP Ratio

Abstract

Symmetrical cells of La0.6Sr0.4CoO3-δ (LSCO) cathode and BaCe0.54Zr0.36Y0.1O2.95 (BCZY) electrolyte (LSCO|BCZY|LSCO) were fabricated by manually painting the respective LSCO cathode slurries onto pellet surfaces of BCZY. The slurries were prepared with different ratios of LSCO to polyvinyl pyrrolidone, PVP as electrode binder (LSCO:PVP). The fabricated cells were denoted as S#1 (5:1/2), S#2 (5:1), S#3 (5:3/2), S#4 (5:2) and S#5 (5:5/2). The contact formation at LSCO|BCZY interface at different ratios of LSCO:PVP was examined by a scanning electron microscope (SEM). SEM images revealed that the LSCO cathode was well adhered onto BCZY electrolyte in all samples without formation of air gap/hole at the interface, except for S#4 and S#5. The elemental composition percentage and formation of air gap/hole at the interface were confirmed by electron dispersive spectroscopy (EDS). The optimum ratio in obtaining a good adhesion between LSCO cathode and BCZY electrolyte is PVP:LSCO = 1/2 – 2 : 5. The polarization resistance (Rp) for the S#1 measured by an electrochemical impedance spectroscopy (EIS) is 0.29 Ωcm2 at 700 °C.