BaCo_0.7Fe_0.22Y_0.08O_3−δ as an Active Oxygen Reduction Electrocatalyst for Low-Temperature Solid Oxide Fuel Cells below 600 °C

Abstract

Solid oxide fuel cells (SOFCs) offer great promise as sustainable energy conversion devices due to their high chemical-toelectrical conversion efficiency, flexible fuel sources, and low pollutions. In recent years, much effort has been devoted to developing intermediate temperature SOFCs. Central to the devices is the availability of a highly effective electrocatalyst for oxygen reduction reaction with reduced temperature operation, especially below 600 °C. Here we present a novel B-site Y-doped perovskitetype oxide BaCo 0.7 Fe 0.22 Y 0.08 O 3−δ (BCFY) with extremely low polarization resistances (e.g., 0.10 Ω cm 2 at 550 °C), which is ascribed to high cubic symmetry structure and fast oxygen kinetics. The superior electrocatalytic activity and stability enable BCFY to be a promising cathode candidate toward the application of reduced temperature SOFCs.

Shaping triple-conducting semiconductor BaCo0.4Fe0.4Zr0.1Y0.1O3-δ into an electrolyte for low-temperature solid oxide fuel cells

“…The electrode polarization resistance also exhibits small values of 0.36–2.04 Ω cm 2 over this temperature range, suggesting a high electrode reaction activity. This should be owed to the cathode functionality of BCFZY that contributed to the electrolyte/cathode region, which leads to fast oxygen reduction reaction (ORR) kinetics at the BZFCY-ZnO/NCAL interface 14,15 .…”

“…For instance, operation of a ceramic fuel cell using a typical proton electrolyte BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-δ (BCZYY) and a triple charge (H + /O 2− /e − ) conducting cathode BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BCFZY) was successfully demonstrated at low temperatures, exhibiting a considerable power output of 445 mW cm −2 at 500 °C and possible operation at 350 °C 14 . As a doped derivative of H + /O 2− conducting BaZr x Y 1−x O 3-δ (BZY), the cathode BCFZY gains remarkably activated electron-hole conductivity via heavy B-site doping with Co and Fe while maintaining its high ionic conductivity, leading to good catalytic activity and triple conduction 14,15 . In another featured breakthrough study with respect to protonic perovskite materials, a nickelate SmNiO 3 (SNO) possessing high initial ionic and electronic conductivity can be utilized as an electrolyte in a LT-SOFC, revealing a peak power output of 225 mW cm −2 at 500 °C along with sufficient open-circuit voltage (OCV) of 1.03 V 16 .…”

High-Throughput Computational Screening of Cubic Perovskites for Solid Oxide Fuel Cell Cathodes

“…7,35 In addition to this, recent experimental works on perovskites attribute the high performance of oxygen exchange to low ASR. 9,13,14 Hence, to estimate the SOFC performance, developing a calculable relationship between Evac and ASR data of perovskite-based materials is useful. Typically, the oxygen atom vacancies in perovskites facilitate a fast diffusion of oxygen ions.…”

Self-Assembled Triple (H+/O2−/e−) Conducting Nanocomposite of Ba-Co-Ce-Y-O into an Electrolyte for Semiconductor Ionic Fuel Cells

“…BCY, as one of the doped barium cerates, which presents mixed proton and electronic conductivity [48], can be found in the whole area of the electrolyte, but the content reduces from the anode side to the cathode side. Meanwhile BCO as one of the barium cobalt oxides which presents mixed oxygen ion and electronic conductivity [49] assembles near to the cathode side. As shown in Figure 8, a double layer configuration of the electrolyte can be formed spontaneously.…”

“…BCY, as one doped barium cerates, which presents mixed proton and electronic conductivity [4 be found in the whole area of the electrolyte, but the content reduces from the anod to the cathode side. Meanwhile BCO as one of the barium cobalt oxides which pr mixed oxygen ion and electronic conductivity [49] assembles near to the cathode si shown in Figure 8, a double layer configuration of the electrolyte can be formed sp neously. Additionally, the reduction of the Ce 4+ to Ce 3+ in the reducing atmosphe provide a shuttle for the transportation of protons along the surface of CeO2 particle Ce 4+ can be balanced by Ce 3+ and H + to maintain the charge compensation for neu without the formation of the conventional oxygen vacancy [50].…”