Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures

Sea-Fue Wang; Yi-Le Liao; Yung-Fu Hsu; Piotr Jasiński

doi:10.1016/j.ijhydene.2022.09.148

Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures

Abstract

Three low-temperature solid oxide fuel cells are built using Sm0.2Ce0·8O2-δ (SDC) as the electrolyte. Cell A is symmetrical and features Ni–LiNi0.8Co0·15Al0·05O2 (Ni–NCAL) electrodes, Cell B comprises a Ni–NCAL anode and a Ni–Ag cathode, and Cell C is fabricated using a Ni–NCAL cathode and a Ni–Ag anode. The ohmic resistance and polarization resistance (Rp) of Cells B and C are significantly higher than those of Cell A. The reduction of NCAL at the anodes of Cells A and B yields LiOH and Li2CO3 phases, and the Ni particles generated on the surfaces of the NCAL particles improve the catalytic activity of the cells. Li2CO3–LiOH melts at temperatures >450 °C and penetrates the porous SDC electrolyte layer, causing its densification and abnormal grain growth and increasing its ionic conductivity to >0.2 S/cm at low temperatures. The high open-circuit voltages (OCVs) (0.970–1.113 V) of the cells during electrochemical measurements are ascribed to the Li2CO3–LiOH phase which serves as an electron-blocking layer for the SDC electrolytes. As the reduction of NCAL approaches completion, the anode comprises only Ni phase, which hinders the charge transfer process. The triple-phase-boundary (TPB) area at cathode of Cell B is significantly lower than that of Cell A; therefore, the catalytic activity of Cell B for the oxygen reduction reaction is lower than that of Cell A. Consequently, the maximum power density (MPD) of Cell B is less than half of that of Cell A. The large Rp value of Cell C is ascribed to its low TPB area at Ni–Ag anode which has no reaction with H2 during operation. No visible sintering of the SDC electrolyte layer is observed for Cell C; therefore, its ionic conductivity is considerably smaller than those of the electrolyte layers of Cells A and B. The OCVs of Cell C (0.281–0.495 V) are significantly lower than the typical OCVs of ceria-based SOFCs. This is attributed to the porous SDC electrolyte layer of Cell C. The large Rp values and the low OCVs contribute to the low MPDs of Cell C at various temperatures.

Citations

1 2

CrossRef
0

Web of Science
1 0

Scopus

Authors (4)

Sea-Fue Wang
- Department of Materials and Mineral Resources Engineering, National Taipei University of Technology
Yi-Le Liao
- Department of Materials and Mineral Resources Engineering, National Taipei University of Technology
Yung-Fu Hsu
- Department of Materials and Mineral Resources Engineering, National Taipei University of Technology
Piotr Jasiński prof. dr hab. inż.

Cite as

Full text

full text is not available in portal

full content of the article see on external site open in new tab

Keywords

SOLID OXIDE FUEL CELL NCAL ELECTRODE POLARIZATION CELL PERFORMANCE

Details

Category:

Articles

Type:

artykuły w czasopismach

Published in:

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY no. 47, pages 40067 - 40082,
ISSN: 0360-3199

Language:

English

Publication year:

2022

Bibliographic description:

Wang S., Liao Y., Hsu Y., Jasiński P.: Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures// INTERNATIONAL JOURNAL OF HYDROGEN ENERGY -Vol. 47,iss. 94 (2022), s.40067-40082

DOI: