Organic acids as electrostatic dispersing agents to prepare high quality particulate thin film

Abstract

A simple electrophoretic method is developed for the fabrication of high quality electrolyte film on NiO-YSZ anode substrate for solid oxide fuel cell (SOFC) application. Aromatic carboxylic acids viz. benzoic acid and trimellitic acid have been explored as electrostatic stabilizer to prepare yttria stabilized zirconia (8YSZ) suspensions in isopropanol medium. Systematic studies on different suspension properties and deposition kinetics are carried out for each stabilizing agent to optimize the suspension chemistries and deposition conditions. Successful cathodic deposition has been achieved on polymer coated NiO-YSZ anode substrate using both benzoic acid and trimellitic acid as charging agents. Upon co-firing at 1400 °C, these films resulted in well-adhered dense YSZ coating (thickness: 7–12 μm) on the porous anode substrate. SOFC coupon cells are then fabricated by screen-printing La0.65Sr0.3MnO3 cathode layer on the top of the electrolyte. Maximum current densities as obtained from these single cells vary in the range of 1.3–1.6 A/cm2 for a cell voltage of 0.7 at 800 °C.