Flame spray synthesis and characterisation of stabilised ZrO2 and CeO2 electrolyte nanopowders for SOFC applications at intermediate temperatures

Abstract

by a liquid-fed one-step flame spray synthesis from waterbased solutions, or cost-effective rare earth nitrates with a high water content. It was found that this one-step synthesis, based on an acetylene-supported flame is able to produce phase pure and highly crystalline, nanoscale electrolyte materials. The assynthesised powders show a cubic lattice structure independent of production rates. Specific surface areas of the powders were adjusted between 20 and 60 m 2 g −2, where the latter is an upper limit for the further processing of the powders in terms of screen printing. The influence of process parameters on morphology, particle size, composition, crystallinity, lattice parameter, shrinkage behaviour and coefficient of thermal expansion of the as-synthesised powders were systematically investigated by transmission electron microscopy (TEM), nitrogen adsorption (BET), X-ray diffraction (XRD) and dilatometry. Electrochemical impedance spectroscopy (EIS) was applied at temperatures between 300°C and 900°C and confirmed the high quality and the competitive electrochemical behaviour of the produced powders.

Flame Spray Synthesis of Nanoscale La0.6Sr0.4Co0.2Fe0.8O3–δ and Ba0.5Sr0.5Co0.8Fe0.2O3–δ as Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells

“…However, beside these observations, the huge expansion mismatch of Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-d to common electrolytes (i.e. TEC 8YSZ = 11.6 × 10 -6 K -1 and TEC 20GCO = 14.4 × 10 -6 K -1 [7]) will raise further inconveniences.…”

“…Flame spray synthesis (FSS) is a well-established method to reach a high output of nanoscale materials by using costeffective and easy to handle metal-organic precursors, which is of significant importance for a semi-industrial or large-scale powder production for SOFC applications [6][7][8]. Conditioning steps like grinding, washing, drying or heat treatment and intensive milling steps, as they have to be carried out in solid state reactions, spray pyrolysis, glycine-or wet phase processes [9,10] can be completely avoided in such an aerosol-based flame synthesis [8,[11][12][13].…”

Effects of Ni doping on the sintering and electrical properties of BaZr 0.8 Y 0.2 O 3− δ proton conducting electrolyte prepared by Flame Spray Synthesis

“…Compared to other techniques for the synthesis of nanopowders, FSS has the http://dx.doi.org/10.1016/j.jeurceramsoc.2015.09.010 0955-2219/© 2015 Elsevier Ltd. All rights reserved. advantage to allow a large scale production (up to 1 kg h −1 ) and avoid time consuming and contaminating steps like pre-calcination or intensive milling of the powder [16,17].…”

Effects of rapid process on the conductivity of multiple elements doped ceria-based electrolyte

“…In general, nanoparticles show a higher catalytic activity, better sinterability, better conductivity and other unusual properties contrary to that of bulk materials [18]. Lately, many chemical methods have been developed to synthesize ceria-based electrolyte nanoparticles, including precipitation [19], aerosol flame deposition [20,21], glycine-nitrate combustion [22], citric acid-based sol-gel process [23], laser evaporation [24], freeze-drying [25] and hydrothermal preparation [26] among others. The sintering temperature is substantially lowered by chemically synthesized powders and by the addition of sintering aids [15].…”