The Rheology of Stabilised Lanthanum Strontium Cobaltite Ferrite Nanopowders in Organic Medium Applicable as Screen Printed SOFC Cathode Layers

The production and optimisation of screen printing (SP) pastes containing La_0.58Sr_0.42Co_0.21Fe_0.79O_{3 – δ} and La_0.61Sr_0.41Co_0.19Fe_0.79O_{3 – δ} (LSCF) were investigated. The application of these nanopowders is supposed to improve the cathode's microstructure and increase its mechanical strength. Thirty seven pastes containing LSCF were carried out with variation in binders, dispersants and different particle size distribution. The rheological behaviour of these pastes was investigated. It was found that commercially available dispersant Solsperse 3000 resulted in the best suspension stability, achieving almost 55 times lower viscosity value for pastes containing 20 vol.‐%, than pastes without any dispersants. The shear thinning behaviour was found to be favourable for the LSCF cathode deposition. A cathode made from the mixture of nano and submicron powder exhibits a polarisation resistance as low as 0.76 Ω cm² at 592 °C.