Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1293807 | Journal of Power Sources | 2010 | 8 Pages |
Abstract
Nanocomposite NiO/YSZ powders for high performance anodes of SOFCs have been synthesized via a microwave-assisted complex-gel auto-combustion approach using nitrates of Ni2+, Zr4+ and Y3+, citric acid (CA) and ethyl glycol as starting materials. The complexing conditions including pH and molar ratio of CA to the metal ions in the aqueous solutions have been quantitatively analyzed and optimized to realize their complete chelating into the CA-based gel network. The processing features and the microstructural characteristics of NiO/YSZ phases formed during auto-combustion of gels have been investigated by FT-IR, TG-DSC, XRD, SEM, SAED and HRTEM. It has been found that the nanoscale composite powders of NiO/YSZ, directly obtained through the in situ auto-combustion reactions within the gels, are composed of loosely agglomerated particles with sizes of â¼200 nm, while these particles themselves are the aggregates of finer NiO and YSZ crystallites of â¼15 nm in size. Moreover, the anodes prepared with such nanoscale composite powders have been manifested to possess much better electrochemical properties than the ones obtained by normal NiO/YSZ powder (â¼2.5 μm) according to their measurements of AC impedance and temperature programmed reduction behavior due to the highly enhanced three-dimensional transport network of oxide ions and triple-phase boundaries for surface reactions.
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Authors
Cai Tongxiang, Zeng Yanwei, Zhang Wei, Guo Cuijing, Yang Xiaowei,