Study Of The Anode Half Cell System Of Planner Intermediate Temperature SOFC

Solid Oxide Fuel Cell (SOFC) is considered as a very promising electricity generating device in the future because of its numerous virtues such as high efficiency, low contamination and stuff. In this paper, the preparation technology of electrolyte and anode were studied to improve the performance of SOFCs. The preparation technology of planar anode support SOFC was investigated.Firstly, the tape-casting technology for the electrolyte preparation was improved. The open circuit voltage(OCV) of the electrolyte materials made by mixing different sized TOSOH YSZ and JC YSZ powders reached 1.1V. SEM image showed that the electrolyte was dense. The thickness of the electrolyte was reduced from 20μm to 15μm, thereby decreasing the impedance of the electrolyte and increasing the the power density of the cells by 12.2% at the operating temperature of 800℃. Adding small amount (0.5 mass%) of Al2O3 into the electrolyte can increase the ionic conductivity of 8YSZ due to a decrease in the grain boundary impedance. Moreover, the preparation of electrolyte by screen-printing methode was also investigated.Secondly, the anode functional layer and anode support were improved. The 30mass% PMMA were prepared by tape casting. The structure of the anode support layer was improved by adding 30 mass% of PMMA into it. The porosity of the anode support was 60%. According to the SEM images, the round pores in the support layer took on a continuous pore structure, which supplied enough paths for gas diffusions.Furthermore, pure NiO powders with the average particle size of 33nm were synthesized by the coprecipitation method. Electrochemical performance of anodes prepared with different sized NiO was studied according to the discharging curve. Test result showed that the three phase boundary of the anode prepared with the nano-scaled NiO was enlarged and the power density of the cell prepared with such anodes was increased by 49.9%. Ideal anode microstructure was formed by adding the large sized TOSOH YSZ materials into the anode support layer. Composite NiO/YSZ powders were prepared by Pechini method. SEM images of the anode prepared with the composite NiO/YSZ powders showed that the YSZ particles in the anode covered the NiO and the cell composed of such anodes possessed a maximum power density of 500mW·cm-2. Study result showed an intermediate layer added into the functional layer and the support layer can increase the TPB of the anode and hamper the impurity diffusion from the support layer. The cell composed this kind of anode had a maximum power density of 638 mW·cm-2 at 800℃. Additionally, the sintering techonoly was improved and a piece of smooth ceramic was prepared.Finally, a piece of smooth ceramic with the aeras of 90×90 was prepared by optimal anode and electrolyte technology.