Integration of spin-coated nanoparticulate-based La_0.6Sr _0.4CoO_3-δ cathodes into micro-solid oxide fuel cell membranes

Thin cathodes for micro-solid oxide fuel cells (micro-SOFCs) are fabricated by spin-coating a suspension of La_0.6Sr_0.4CoO _3-δ (LSC) nanoparticulates obtained by salt-assisted spray pyrolysis. The resulting 250 nm thin LSC layers exhibit a three-dimensional porous microstructure with a grain size of around 45 nm and can be integrated onto free-standing 3 mol.% yttria-stabilized-zirconia (3YSZ) electrolyte membranes with high survival rates. Weakly buckled micro-SOFC membranes enable a homogeneous distribution of the LSC dispersion on the electrolyte, whereas the steep slopes of strongly buckled membranes do not allow for a perfect LSC coverage. A micro-SOFC membrane consisting of an LSC cathode on a weakly buckled 3YSZ electrolyte and a sputtered Pt anode has an open-circuit voltage of 1.05 V and delivers a maximum power density of 12 mW cm^-2 at 500 °C.