Tailoring the O2 reduction activity on hydrangea-like La0.5Sr0.5MnO3 cathode film fabricated via atmospheric pressure plasma jet process

An atmospheric-pressure plasma jet (APPJ) is applied to prepare porous perovskite materials, particularly of lanthanum strontium manganite La0.5Sr0.5MnO3 (LSM551) oxide powder and film. LSM nano powder around 50.0 nm is obtained, and characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscope. A spherical morphology with hydrangea-like shape is observed as associates to the pure tetragonal phase. LSM film is deposited onto yttria-stabilized zirconia (YSZ) electrolyte-support substrate as cathode layer for the operation in a solid oxide fuel cell at 600-900 °C operating temperatures. A series of symmetrical cells possessing high exchange current density of 30.12 mA/cm2 at 800 °C. The prepared samples are assessed as an object to discover the diffusion mechanism of oxygen pathways for LSM/YSZ system based on the microstructural (particles size, and porosities) and electrochemical (kinetic and impedance) data. The mechanism of oxygen pathways is directly associated with the triple phase boundary lengthiness, in which the surface and bulk pathways occurring in APPJ-prepared LSM layer on YSZ lead to an increasing in activity of oxygen reduction reaction. Moreover, a fabrication of desirable ternary metal oxide, LSM, with highly porous structure via an advance-innovative APPJ preparation is outlined.