Role of Electrode Binder on Contact Formation between La0.6Sr0.4CoO3-? Cathode and Yttrium Doped Cerate-Zirconate Solid Electrolyte

Abstract

Powder of La_0.6Sr_0.4CoO_3-? (LSCO) was synthesized by a combined citrate-EDTA synthesis route. The high purity of LSCO cathode powder as confirmed by X-ray diffraction (XRD) analysis was prepared to become cathode slurries using different electrode binders namely polyvinyl alcohol (PVA), polyvinyl butyral-co-vinyl alcohol-co-vinyl acetate (PVB), polyvinyl pyrrolidone (PVP), ethyl cellulose (EC) and ethylene glycol (EG). These slurries were separately painted on the pellet surfaces of BaCe_0.54Zr_0.36Y_0.1O_2.95 (BCZY) solid electrolyte to fabricate symmetrical cell of LSCO/BCZY/LSCO. The role of electrode binder on contact formation between LSCO and BCZY was investigated. The contact formation at LSCO/BCZY interface was examined by Scanning Electron Microscope equipped with Electron Dispersive Spectroscopy (SEM/EDS). Three distinct areas corresponding to the LSCO cathode, BCZY electrolyte and LSCO/BCZY interface with free or crack/hole was observed in the SEM micrographs. The elemental compositions at these three areas were confirmed by EDS and their percentage was presented. The cells prepared with the aid of EC, EG, PVA and PVB showed poor contact between LSCO and BCZY due to the presence of the crack and/or hole (air gap) at interface except for the cell prepared with PVP. Therefore, PVP plays an important role in making a good contact between LSCO cathode and BCZY electrolyte.

Keywords: La_0.6Sr_0.4CoO_3-? cathode, BaCe_0.54Zr_0.36Y_0.1O_2.95 electrolyte, electrode binder, SEM/EDS