Preparation And Properties Of Anode Supported Single Chamber Solid Oxide Fuel Cells

Single-chamber solid oxide fuel cell, which can start quickly without sealing, is a new structure of fuel cell. It is operated by different catalytic selectivity of cathode to oxygen and anode to the fuel (usually hydrocarbons or hydrogen) to produce potential. In recent years, single-chamber solid oxide fuel cell has developed rapidly in China and abroad. The research of SC-SOFC is focused on the choice of electrode and electrolyte materials, optimization of operating conditions and structural design of the battery.In this thesis, an anode supported SC-SOFC, Ni-YSZ| YSZ| LSM was first prepared by double powder dry-pressing method. The electrode material performance was comprehensively characterizated by XRD, SEM, BET and conductivity measurements. The composition of battery materials was optimized. The electrochemical performance, such as open circuit voltage, power density and cell stability were analysized by electrochemical working station under different test conditions. The best operation condition was O2:C3H8= 2 at 400 sccm at 700℃.To further improve the output performance of battery, some materials with high catalysis and electrical conductivity, such as LSTM, SSCM, LSCM were chosed to prepare the cathode of battery and then the effect of sintering temperature to battery performance was examed. The results indicated that LSCM had the best performance. On this basis, YSZ with the ionic conductivity, as a second phase, was added to the LSCM cathode to form a composite cathode. The output power density reached 81 mW/cm2 with the ratio of 30%YSZ in the composite cathode. Gradient cathode was further formed between electrode and electrolyte layers. The "Sandwich" cell, Ni-YSZ|YSZ|CGO|50LSCM-50CGO|LSCM, had a maximum power density of 11 OmW/cm2. The performance was increased by 50%. Thus, this cathode design can be widely applied to the cathode preparation in SC-SOFC. For the anode, the mixed conducting layer was added to anode/electrolyte interface. Adding a small amount of metal catalyst by dip-coating method and doubie powder dry-pressing method were benefit for improving the catalytic activity of anode. 50Ni-5Fe-45YSZ| YSZ| CGO| 50LSCM-50CGO| LSCM, which is prepared by doubie powder dry-pressing method, reached the maximum power density of 129mW/cm2.It is increased by 17%, compared to the "Sandwich" cell. This improvement is due to the catalytic synergy effect by Fe and Ni. This is expected that Fe-Ni compound metal can be widely applied to anode materials in SC-SOFC.