Enhancing the performance of symmetrical solid oxide fuel cells with Sr2Fe1.5Mo0.5O6-δ electrodes via infiltration of Pr6O11 bifunctional catalyst. (10th January 2022)

• Record Type: Journal Article
• Authors: Zhu, Zongchao; Sun, Keqiang; Xu, Dong; Gu, Yiheng; Ni, Qing; Zheng, Yifeng; Chen, Han; Ge, Lin; Huang, Xiaogu; Guo, Lucun
• Is Part Of: Electrochimica acta. Volume 402(2022)
• Publication Date: 2022-01-10
• Subjects: Symmetrical solid oxide fuel cells -- Thin YSZ substrates -- Symmetrical electrodes -- Pr6O11 -- Bifunctional catalyst; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139569
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Thin YSZ (∼40 μm) self-supporting SSOFC with Sr2 Fe1.5 Mo0.5 O6-δ electrodes were prepared. Symmetrical Pr6 O11 infiltration increased the power output from 301 mW/cm 2 to 455 mW/cm 2 (H2, 800 °C). Pr6 O11 simultaneously boosted H2 oxidation (HOR) and O2 reduction (ORR). Abstract: Symmetrical solid oxide fuel cells based on yttrium-stabilized zirconia (YSZ) electrolyte and Sr2 Fe1.5 Mo0.5 O6-δ (SFM) electrode are prepared via phase-inversion and impregnation processes. The YSZ symmetrical electrolyte support is constructed using two porous frameworks and one thin-dense-membrane via phase-inversion combined with drip-coating techniques. SFM is infiltrated into the porous frameworks of the symmetric YSZ support to work as electrodes. Nanoscale Pr6 O11 catalysts are further infiltrated into the electrodes to promote electrochemical performance. The optimal loading of SFM and Pr6 O11 are systematically investigated. At 800 °C, with the optimal loading of SFM (12 wt%), the polarization resistance ( Rp ) for anode and cathode of the cell decrease to 0.19 and 0.10 Ω cm 2, respectively. The maximum power density (MPD) achieves 301 mWcm −2 in H2 at 800 °C. After loading Pr6 O11, the Rp for anode and cathode further decrease by 47% to 0.10 Ωcm 2 and by 80% to 0.021 Ωcm 2, respectively. And the MPD improves by 51% to 455 mWcm −2 (at 800 °C). These results and analysis of distribution of relaxation times demonstrate that the introduction of Pr6 O11 as bifunctional catalysts is a promising approach for simultaneously improving H2 fuel oxidation and O2 reduction activities. Graphical abstract: Symmetric solid oxide fuel cells based on thin YSZ self-supporting "porous | dense | porous" electrolyte backbone and Sr2 Fe1.5 Mo0.5 O6-δ electrodes were prepared. Then symmetrical Pr6 O11 infiltration simultaneously boosted H2 oxidation (anode) and O2 reduction (cathode). Image, graphical abstract