A micro-nano porous oxide hybrid for efficient oxygen reduction in reduced-temperature solid oxide fuel cells

摘要

Tremendous efforts to develop high-efficiency reduced-temperature (≤ 600°C) solid oxide fuel cells are motivated by their potentials for reduced materials cost, less engineering challenge, and better performance durability. A key obstacle to such fuel cells arises from sluggish oxygen reduction reaction kinetics on the cathodes. Here we reported that an oxide hybrid, featuring a nanoporous Sm_0.5Sr_0.5CoO_3?δ (SSC) catalyst coating bonded onto the internal surface of a high-porosity La_0.9Sr_0.1Ga_0.8Mg_0.2O_3?δ (LSGM) backbone, exhibited superior catalytic activity for oxygen reduction reactions and thereby yielded low interfacial resistances in air, e.g., 0.021 Ω cm2 at 650°C and 0.043 Ω cm2 at 600°C. We further demonstrated that such a micro-nano porous hybrid, adopted as the cathode in a thin LSGM electrolyte fuel cell, produced impressive power densities of 2.02?W cm?2 at 650°C and 1.46?W cm?2 at 600°C when operated on humidified hydrogen fuel and air oxidant.. ? 2012 Macmillan Publishers Limited. All rights reserved