Boosting power density of solid oxide fuel cells by synergistic effect of nanocomposite cathode and anode

Abstract

Solid oxide fuel cells (SOFCs) are currently used as highly efficient devices, but further high power density is needed for their widespread commercialization. The present work reports high-performance nanocomposite cathode layer and anode functional layer (AFL), and the exceptional improvement in power density of SOFCs achieved by applying these nanocomposite layers. For these layer materials, two types of nanocomposite particles are synthesized via spray pyrolysis, i.e., strontium-doped samarium cobaltite (SSC) and samarium-doped ceria (SDC) for the cathode, and NiO and yttria-stabilized zirconia (YSZ) for the AFL, which are of submicrometer-scale secondary particles formed with nanometer-scale crystallites. Both the SSC-SDC nanocomposite cathode layer and the Ni-YSZ nanocomposite AFL show three-dimensional ultrafine structures with highly active large triple-phase boundary region and conducting network pathways. The distribution of relaxation times and fitting analysis for the anode-supported SOFCs reveals that these nanocomposite cathode and anode effectively improve the electrochemical reactions of each electrode by lowering the electrode polarization resistance. The maximum power density of such SOFCs reaches extremely high values of 4.96, 4.05, 2.68, 1.34, and 0.63 W cm−2 at 800, 750, 700, 650, and 600 °C, respectively.