Design of experiment approach applied to reducing and oxidizing tolerance of anode supported solid oxide fuel cell. Part I: Microstructure optimization

作者：Faes Antonin^*; Fuerbringer Jean Marie; Mohamedi Driss; Hessler Wyser Aiecha; Caboche Gilles; Van Herle Jan

来源：Journal of Power Sources, 2011, 196(17): 7058-7069.

DOI：10.1016/j.jpowsour.2010.07.092

• RedOx stability
• Ni-YSZ anode supported cell
• Solid oxide fuel cell
• Design of experiment
• Surface response methodology
• Conductivity

The main drawback of Ni/YSZ anode supports for solid oxide fuel cell application is their low tolerance to reducing and oxidizing (RedOx) atmosphere changes, owing to the Ni/NiO volume variation. This work describes a structured approach based on design of experiments for optimizing the microstructure for RedOx stability enhancement. A full factorial hypercube design and the response surface methodology are applied with the variables and their variation range defined as: (1) NiO proportion (40-60 wt% of the ceramic powders), (2) pore-former proportion (0-30 wt% corresponding to 0-64 vol.%), (3) NiO particle size (0.5-8 mu m) and (4) 8YSZ particle size (0.6-9 mu m).
To obtain quadratic response models, 25 different compositions were prepared forming a central composite design. The measured responses are (i) shrinkage during firing, (ii) surface quality, (iii) as-sintered porosity, (iv) electrical conductivity after reduction and (v) expansion after re-oxidation. This approach quantifies the effect of all factors and their interactions. From the quadratic models, optimal compositions for high surface quality, electrical conductivity (>500 S cm(-1) at room temperature) and RedOx expansion (<0.2% upon re-oxidation) are defined. Results show that expansion after re-oxidation is directly influenced by the sample porosity whereas, surprisingly, the NiO content, varied between 40 and 60 wt%, does not show any impact on this response.

• 出版日期2011-9-1