Tailoring gadolinium-doped ceria-based solid oxide fuel cells to achieve 2 W cm−2 at 550 °C

Abstract

Low-temperature operation is necessary for next-generation solid oxide fuel cells due to the wide variety of their applications. However, significant increases in the fuel cell losses appear in the low-temperature solid oxide fuel cells, which reduce the cell performance. To overcome this problem, here we report Gd 0.1 Ce 0.9 O 1.95 -based low-temperature solid oxide fuel cells with nanocomposite anode functional layers, thin electrolytes and core/shell fibrestructured Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3 À d -Gd 0.1 Ce 0.9 O 1.95 cathodes. In particular, the report describes the use of the advanced electrospinning and Pechini process in the preparation of the core/shell-fibre-structured cathodes. The fuel cells show a very high performance of 2 Wcm À 2 at 550°C in hydrogen, and are stable for 300 h even under the high current density of 1 A cm À 2 . Hence, the results suggest that stable and high-performance solid oxide fuel cells at low temperatures can be achieved by modifying the microstructures of solid oxide fuel cell components.

Corn-cob like nanofibres as cathode catalysts for an effective microstructure design in solid oxide fuel cells

“…Especially, at the general SOFC operation temperature of 800 o C, the resistance for the corn-cob nanofiber with LSM shell and YSZ core shows the lowest value which is lower than the data reported in other literatures, expecting to have high single cell performance. 31 As shown in Figure 6, these great improvements of the prepared corn-cob nanofiber catalysts were directly translated to the SOFC single cell tests to prove the possibility of using our new electrode structure to the real full cell system. Figure S4) and good sealing in the test apparatus.…”

“…These continuous nanofibers transferred electrons and oxygen ions, respectively, better to the whole electrode with less interruption. 27,[31][32] Furthermore, from the formation of unique microstructure structure by a nanofibrous web, higher surface area of the architected nanostructure was created, which is greatly related to the large number of active reaction sites.…”

“…28,31 Furthermore, Mingjia Zhi et al reported an YSZ scaffold mat infiltrated with LSM as a mixed (ionic and electronic) conducting cathode. 32 This showed an improved oxygen reduction properties by reducing the polarization resistance, which is due to the continuous path of charge transport for both oxide ions and electrons.…”

A Nanostructured Architecture for Reduced‐Temperature Solid Oxide Fuel Cells

“…[ 13 ] Power densities reported here were also 20-30% higher than those obtained at 550-600 °C for our prior metal-supported fuel cells with similar nano-SDC/Ni@430L anodes and SSZ electrolytes, but with in situ sintered ESB-Ag cathodes (e.g., 0.77 W cm −2 at 600 °C). [ 18 ] Although there are prior reports of excellent all-ceramic fuel cells that produced power densities of ≈1 W cm −2 at 500-550 °C, they were obtained with much more conductive electrolytes such as Gd 3+ -doped ceria [ 21 ] or strontium-and magnesium-doped lanthanum gallate. [ 8,19 ] Electrochemical impedance spectroscopy (EIS) was used to better understand the electrode reactions and quantitatively determine their contributions to the internal resistances.…”

Selected aspects of the design and diagnostics of solid oxide fuel cells

“…The application of some oxygen ionic conductors as well as proton conducting ceramics, which exhibited higher ionic conductivity than 8YSZ at intermediate temperature range seem to be most often considered solution. Ceria-based solid electrolytes still seem to be the most attractive oxide conducting ceramic membranes at intermediate temperature ranges (600-800 o C) [15][16][17]. The utilization of ceramic proton conducting membrane instead to oxygen ionic conductor as an electrolyte in SOFCs can lead to simplification of the SOFC stacks construction.…”