Fabrication of a dense La0.2Sr0.8CoO3−δ/CoO composite membrane by utilizing the electroless cobalt plating technique

Fabrication of dense ceramic electrolyte membranes on porous supports is a key step towards performing gas separations (H2 or O2) through the electrochemical pathway. This research develops an approach by making use of the electroless plating method for the preparation of metal-ceramic composite membrane, which is used as the precursor to a metal-oxide composite membrane. As a model of the composite membrane, metallic cobalt is incorporated into a powder-packed layer of La0.2Sr0.8CoO3−δ (LSCO-80), which is pre-coated on a porous MgO disk. When this composite membrane is subjected to sintering at 1000 °C in air, an interpenetrating laminar structure consisting of CoO and LSCO-80 phases is formed according to the cross-section EDX profiles. The oxidation of Co during sintering causes a structure expansion, which exerts a compressive stress on LSCO-80 phase, thus effectively buffering a tensile stress applied by the support. As a result, the composite membrane LSCO-80/CoO can achieve almost gas-tight at ambient temperature.