Modification of Cell Microstructure and Compositions for High and Stable Performance of Low-temperature SOFCs

摘要

High ohmic resistance and high electrode overpotentials are the main obstacles for the development of low temperature SOFCs (LT-SOFCs). In this work, we demonstrate three approaches to obtain significantly improved cell performance for anode-supported cell (ASC) at an operating temperature of 600°C. First, La_(0.6)Sr_(0.4)CoO3 (LSC) has been introduced as cathode material aiming for the reduction of the electrode polarization resistance. Second, thin and dense CGO barrier layers manufactured by physical vapor deposition technique (PVD) and reactive spray deposition technology (RSDT) have been applied between the cathode and electrolyte to diminish the ohmic losses. For comparison, a CGO barrier layer prepared by screen printing has been included. The third one is the modification of the manufacturing process of the anode substrate, aiming for controlled microstructure with high porosity that leads to reduced gas diffusion resistance. These three modification steps resulted in significant improvement of cell performance. Approximately 75% higher maximum power density has been obtained at 600°C.