TY - JOUR
T1 - Performance evolution analysis of a solid oxide cell operated in fuel-cell, electrolysis and cycle modes
AU - Cui, Tonghui
AU - Lyu, Zewei
AU - Han, Minfang
AU - Sun, Kaihua
AU - Liu, Yang
AU - Ni, Meng
N1 - Funding Information:
This work is supported by the National Natural Science Foundation of China ( NSFC 5201101243 ), and Tsinghua University State Key Lab Program ( SKLD21M15 ). The authors would like to acknowledge colleagues in Tsinghua SOFC Lab and Huatsing Energy group for technical assistance and fruitful discussions.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/6/15
Y1 - 2022/6/15
N2 - Solid oxide cells (SOCs) are especially important in the context of a boom in the intermittent renewable energy. However, the widespread commercialization of SOCs is still constrained by stability. To investigate the performance evolution mechanisms, fuel-cell, electrolysis, and reversible operations of an industrial-size (10 cm × 10 cm) SOC were conducted. The electrochemical impedance spectroscopy (EIS) measured under open-circuit/a small DC bias and operating current was analyzed employing the distribution of relaxation times (DRT) method and equivalent circuit model (ECM) fitting. Under the fuel-cell and electrolysis modes, the resistances corresponding to the electrode processes held different change trends with increasing DC biases. Compared with the fuel-cell mode, the proportion of the resistance related to the gas diffusion and conversion processes of the fuel electrode was higher in the electrolysis mode. Meanwhile, the resistances associated with the charge transfer reaction, gas diffusion and conversion processes of fuel electrode increased faster in the electrolysis mode. Besides, through the evolution of j-V curves and resistances of electrode processes, the whole operation process was divided into the initial stage (first activation and then rapid-degradation) and the stable stage. In the post-mortem analysis, Ni non-percolating, Ni coarsening and change of pore morphology in the fuel electrode were mainly observed. Combined with the detailed EIS analysis and microstructure changes, the dominant performance evolution mechanism in different stages of the overall operation process was proposed.
AB - Solid oxide cells (SOCs) are especially important in the context of a boom in the intermittent renewable energy. However, the widespread commercialization of SOCs is still constrained by stability. To investigate the performance evolution mechanisms, fuel-cell, electrolysis, and reversible operations of an industrial-size (10 cm × 10 cm) SOC were conducted. The electrochemical impedance spectroscopy (EIS) measured under open-circuit/a small DC bias and operating current was analyzed employing the distribution of relaxation times (DRT) method and equivalent circuit model (ECM) fitting. Under the fuel-cell and electrolysis modes, the resistances corresponding to the electrode processes held different change trends with increasing DC biases. Compared with the fuel-cell mode, the proportion of the resistance related to the gas diffusion and conversion processes of the fuel electrode was higher in the electrolysis mode. Meanwhile, the resistances associated with the charge transfer reaction, gas diffusion and conversion processes of fuel electrode increased faster in the electrolysis mode. Besides, through the evolution of j-V curves and resistances of electrode processes, the whole operation process was divided into the initial stage (first activation and then rapid-degradation) and the stable stage. In the post-mortem analysis, Ni non-percolating, Ni coarsening and change of pore morphology in the fuel electrode were mainly observed. Combined with the detailed EIS analysis and microstructure changes, the dominant performance evolution mechanism in different stages of the overall operation process was proposed.
KW - Ni coarsening
KW - Ni non-percolating
KW - Performance evolution mechanisms
KW - Solid oxide cells
UR - http://www.scopus.com/inward/record.url?scp=85129458652&partnerID=8YFLogxK
U2 - 10.1016/j.enconman.2022.115657
DO - 10.1016/j.enconman.2022.115657
M3 - Journal article
AN - SCOPUS:85129458652
SN - 0196-8904
VL - 262
JO - Energy Conversion and Management
JF - Energy Conversion and Management
M1 - 115657
ER -