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Highly active and durable triple conducting composite air electrode for low-temperature protonic ceramic fuel cells.
- Source :
- Nano Research; Jul2023, Vol. 16 Issue 7, p9280-9288, 9p
- Publication Year :
- 2023
-
Abstract
- Protonic ceramic fuel cells (PCFCs) are more suitable for operation at low temperatures due to their smaller activation energy (E<subscript>a</subscript>). Unfortunately, the utilization of PCFC technology at reduced temperatures is limited by the lack of durable and high-activity air electrodes. A lot number of cobalt-based oxides have been developed as air electrodes for PCFCs, due to their high oxygen reduction reaction (ORR) activity. However, cobalt-based oxides usually have more significant thermal expansion coefficients (TECs) and poor thermomechanical compatibility with electrolytes. These characteristics can lead to cell delamination and degradation. Herein, we rationally design a novel cobalt-containing composite cathode material with the nominal composition of Sr<subscript>4</subscript>Fe<subscript>4</subscript>Co<subscript>2</subscript>O<subscript>13+δ</subscript> (SFC). SFC is composed of tetragonal perovskite phase (Sr<subscript>8</subscript>Fe<subscript>8</subscript>O<subscript>23+δ</subscript>, I4/mmm, 81 wt.%) and spinel phase (Co<subscript>3</subscript>O<subscript>4</subscript>, Fd3̄m, 19 wt.%). The SFC composite cathode displays an ultra-high oxygen ionic conductivity (0.053 S·cm<superscript>−1</superscript> at 550 °C), superior CO<subscript>2</subscript> tolerance, and suitable TEC value (17.01 × 10<superscript>−6</superscript> K<superscript>−1</superscript>). SFC has both the O<superscript>2−</superscript>/e<superscript>−</superscript> conduction function, and the triple conducting (H<superscript>+</superscript>/O<superscript>2−</superscript>/e<superscript>−</superscript>) capability was achieved by introducing the protonic conduction phase (BaZr<subscript>0.2</subscript>Ce<subscript>0.7</subscript>Y<subscript>0.1</subscript>O<subscript>3−δ</subscript>, BZCY) to form SFC+BZCY (70 wt.%:30 wt.%). The SFC+BZCY composite electrode exhibits superior ORR activity at a reduced temperature with extremely low area-specific resistance (ASR, 0.677 Ω·cm<superscript>2</superscript> at 550 °C), profound peak power density (PPD, 535 mW·cm<superscript>−2</superscript> and 1.065 V at 550 °C), extraordinarily long-term durability (> 500 h for symmetrical cell and 350 h for single cell). Moreover, the composite has an ultra-low TEC value (15.96 × 10<superscript>−6</superscript> K<superscript>−1</superscript>). This study proves that SFC+BZCY with triple conducting capacity is an excellent cathode for low-temperature PCFCs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19980124
- Volume :
- 16
- Issue :
- 7
- Database :
- Complementary Index
- Journal :
- Nano Research
- Publication Type :
- Academic Journal
- Accession number :
- 169750678
- Full Text :
- https://doi.org/10.1007/s12274-023-5531-3