Performance degradation shortens the life of solid oxide fuel cells in practical applications.Revealing the degradation mechanism is crucial for the continuous improvement of cell durability.In this work,the effects o...Performance degradation shortens the life of solid oxide fuel cells in practical applications.Revealing the degradation mechanism is crucial for the continuous improvement of cell durability.In this work,the effects of cell operating conditions on the terminal voltage and anode microstructure of a Ni-yttria-stabilized zirconia anode-supported single cell were investigated.The microstructure of the anode active area near the electrolyte was characterized by laser optical microscopy and focused ion beam-scanning electron microscopy.Ni depletion at the anode/electrolyte interface region was observed after 100 h discharge tests.In addition,the long-term stability of the single cell was evaluated at 700℃for 3000 h.After an initial decline,the anode-supported single cell exhibits good durability with a voltage decay rate of 0.72%/kh and an electrode polarization resistance decay rate of 0.17%/kh.The main performance loss of the cell originates from the initial degradation.展开更多
Accurate prediction of performance degradation in complex systems such as solid oxide fuel cells is crucial for expediting technological advancements.However,significant challenges still persist due to limited compreh...Accurate prediction of performance degradation in complex systems such as solid oxide fuel cells is crucial for expediting technological advancements.However,significant challenges still persist due to limited comprehension of degradation mechanisms and difficulties in acquiring in-situ features.In this study,we propose an effective approach that integrates long short-term memory(LSTM) neural network and dynamic electrochemical impedance spectroscopy(DEIS).This integrated approach enables precise prediction of future evolutions in both current-voltage and EIS features using historical testing data,without prior knowledge of degradation mechanisms.For short-term predictions spanning hundreds of hours,our approach achieves a prediction accuracy exceeding 0.99,showcasing promising prospects for diagnostic applications.Additionally,for long-term predictions spanning thousands of hours,we quantitatively determine the significance of each degradation mechanism,which is crucial for enhancing cell durability.Moreover,our proposed approach demonstrates satisfactory predictive ability in both time and frequency domains,offering the potential to reduce EIS testing time by more than half.展开更多
Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in ...Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in Aspen plus.Key operating parameters,such as steam to fuel ratio,stack temperature,reformer temperature,air flow rate,and air preheating temperature,were analyzed.Optimization was conducted based on the simulation results.Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency,but it might decrease the gross system efficiency.Higher stack and reformer temperatures contribute to the electrical efficiency,and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750℃and 700℃,respectively.The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency,the recommended value is around 600℃under the reference condition.展开更多
Gadolinium-doped ceria(GDC)interlayers are required to prevent the interfacial reaction between La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)cathode and Y_(2)O_(3)-stabilized ZrO 2(YSZ)electrolyte in solid oxide fuel ce...Gadolinium-doped ceria(GDC)interlayers are required to prevent the interfacial reaction between La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)cathode and Y_(2)O_(3)-stabilized ZrO 2(YSZ)electrolyte in solid oxide fuel cells(SOFCs).However,it's difficult to prepare a thin and dense GDC interlayer on the sintered half-cell at a low temperature.In this study,the physical vapor deposition(PVD)method was employed to success-fully manufacture dense GDC interlayers with the thickness of 1 m m.The influences of GDC sintering temperature(900℃,1000℃ and 1100℃)on cell performance characteristics and degradation behavior were investigated.The cell with GDC interlayer sintered at 1100?C showed the lowest degradation rate during the 216-h operation.The best stability was attributed to the most effective inhibition of Sr diffusion by the GDC interlayer,which was demonstrated by the almost unchanged Ohmic and polari-zation resistances during the aging stage and the negligible Sr enrichment at YSZ/GDC interface.Compared to the conventional screen-printed GDC interlayers(sintered above 1250℃),the GDC inter-layer prepared by the PVD method and sintered at 1100℃ was significantly denser and thinner,showing a promising application prospect due to its benefits for cell stability.展开更多
基金supported by the National Key R&D Program of China(No.2018YFB1502202)the Fundamental Research Funds for the Central Universities(No.FRF-GF-20-09B).
文摘Performance degradation shortens the life of solid oxide fuel cells in practical applications.Revealing the degradation mechanism is crucial for the continuous improvement of cell durability.In this work,the effects of cell operating conditions on the terminal voltage and anode microstructure of a Ni-yttria-stabilized zirconia anode-supported single cell were investigated.The microstructure of the anode active area near the electrolyte was characterized by laser optical microscopy and focused ion beam-scanning electron microscopy.Ni depletion at the anode/electrolyte interface region was observed after 100 h discharge tests.In addition,the long-term stability of the single cell was evaluated at 700℃for 3000 h.After an initial decline,the anode-supported single cell exhibits good durability with a voltage decay rate of 0.72%/kh and an electrode polarization resistance decay rate of 0.17%/kh.The main performance loss of the cell originates from the initial degradation.
基金partly supported by Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellowships for Research in Japan (P22370)by Key Project of Jiangsu Province (BE2022029) in China。
文摘Accurate prediction of performance degradation in complex systems such as solid oxide fuel cells is crucial for expediting technological advancements.However,significant challenges still persist due to limited comprehension of degradation mechanisms and difficulties in acquiring in-situ features.In this study,we propose an effective approach that integrates long short-term memory(LSTM) neural network and dynamic electrochemical impedance spectroscopy(DEIS).This integrated approach enables precise prediction of future evolutions in both current-voltage and EIS features using historical testing data,without prior knowledge of degradation mechanisms.For short-term predictions spanning hundreds of hours,our approach achieves a prediction accuracy exceeding 0.99,showcasing promising prospects for diagnostic applications.Additionally,for long-term predictions spanning thousands of hours,we quantitatively determine the significance of each degradation mechanism,which is crucial for enhancing cell durability.Moreover,our proposed approach demonstrates satisfactory predictive ability in both time and frequency domains,offering the potential to reduce EIS testing time by more than half.
基金the National Key R&D Program of China(2017YFB0601903).
文摘Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in Aspen plus.Key operating parameters,such as steam to fuel ratio,stack temperature,reformer temperature,air flow rate,and air preheating temperature,were analyzed.Optimization was conducted based on the simulation results.Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency,but it might decrease the gross system efficiency.Higher stack and reformer temperatures contribute to the electrical efficiency,and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750℃and 700℃,respectively.The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency,the recommended value is around 600℃under the reference condition.
基金This work was supported by the National Key R&D Program of China(2018YFB1502202)Tsinghua University Initiative Scien-tific Research Program(20193080038).
文摘Gadolinium-doped ceria(GDC)interlayers are required to prevent the interfacial reaction between La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)cathode and Y_(2)O_(3)-stabilized ZrO 2(YSZ)electrolyte in solid oxide fuel cells(SOFCs).However,it's difficult to prepare a thin and dense GDC interlayer on the sintered half-cell at a low temperature.In this study,the physical vapor deposition(PVD)method was employed to success-fully manufacture dense GDC interlayers with the thickness of 1 m m.The influences of GDC sintering temperature(900℃,1000℃ and 1100℃)on cell performance characteristics and degradation behavior were investigated.The cell with GDC interlayer sintered at 1100?C showed the lowest degradation rate during the 216-h operation.The best stability was attributed to the most effective inhibition of Sr diffusion by the GDC interlayer,which was demonstrated by the almost unchanged Ohmic and polari-zation resistances during the aging stage and the negligible Sr enrichment at YSZ/GDC interface.Compared to the conventional screen-printed GDC interlayers(sintered above 1250℃),the GDC inter-layer prepared by the PVD method and sintered at 1100℃ was significantly denser and thinner,showing a promising application prospect due to its benefits for cell stability.
