Dependence of Electrochemical Performance on Microstructure and Distribution for Ni/YSZ Anode with Y-Doped BaZrO₃ in Solid Oxide Fuel Cells

Abstract

Distribution of proton conductor yttrium-doped barium zirconate (BZY) within a nickel (Ni)/yttria-stabilized zirconia (YSZ) anode was controlled using composite powder prepared by spray pyrolysis, and the dependence of electrode performance on this BZY distribution within the Ni/YSZ anode was investigated to clarify the role of BZY in improving the anode performance when humidified hydrogen or dry methane is the fuel. First, the effective thickness of the Ni/YSZ anode electrochemical reaction was determined, and then BZY was distributed to either the inside or the outside of the effective thickness. The BZY addition inside the effective thickness improved the anode performance and, in contrast, the BZY addition outside did not improve the anode performance, suggesting that the role of BZY is mainly to promote the electrochemical reactions occurring within the effective thickness.

Influence of Reactions of Carbon Black and Fuel Diffusion Process on Power Generation Characteristics of Rechargeable Solid Carbon Fuel Cells(RSCFCs)

“…5b), V was stable at each I. This indicates a stable CO partial pressure at the anode surface because the CO supply rate was equal to the CO consumption rate, which we have thus defined as "steady state" (19). In the horizontal cell setting (Fig.…”

“…The main difficulty in solid oxide DCFCs is effectively supplying the solid carbon to the TPB (Triple Phase Boundary) of the anode microstructure (6)(7)(8)(9)(10)(11)(12)(13)(14). To overcome this difficulty, we developed a Rechargeable Direct Carbon Fuel Cell (RDCFC), which is a carbon-fueled SOFC that uses pyrolytic carbon supplied via thermal decomposition of hydrocarbon gas (15)(16)(17)(18). RDCFCs have a high power density because the pyrolysis of hydrocarbons causes carbon deposition into the anode microstructure.…”

“…In previous study (19), three different methods to supply CB fuel were investigated focusing on direct contact and non-contact between the CB fuel and the anode. A small amount of CB in contact with the anode, i.e., carbon direct oxidation (reactions [3] and [4]), effectively enhanced the performance, particularly during initial power generation.…”

Nanoscopic Ni Interfaced with Oxygen Conductive Supports: Link between Electrochemical and Catalytic Studies

“…Nickel is an inexpensive and abundant metal that has attracted a great deal of attention as a catalytic material in heterogeneous and electro-catalysis (7,9,14,(19)(20)(21)(22)(23)(24)(25). The use of nickel is appealing due to its potential in giving a good catalytic performance, comparable to that of noble metals, while being cost-effective.…”

“…High catalytic activity of Ni/CeO 2 was also reported for water-gas shift reaction (WGS) emphasizing the promotional effect of ceria (22). Furthermore, Ni/YSZ cermet has been used as an anode material in solid oxide fuel cells (SOFC) (21,26,27), because of its high electrocatalytic activity and stability.…”