Advanced Functional Materials
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editor-in-Chief: Joern Ritterbusch, Deputy Editors: Mary De Vita, Yan Li
Online ISSN: 1616-3028
Associated Title(s): Advanced Electronic Materials, Advanced Energy Materials, Advanced Engineering Materials, Advanced Healthcare Materials, Advanced Materials, Advanced Materials Interfaces, Advanced Materials Technologies, Advanced Optical Materials, Advanced Science, Particle & Particle Systems Characterization, Small
Thin-Film Electrodes: Microscopic and Nanoscopic Three-Phase-Boundaries of Platinum Thin Film Electrodes on YSZ Electrolyte (Adv. Funct. Mater. 3/2011)
Agglomerated Pt thin films have been proposed as electrodes for electrochemical devices like micro-solid oxide fuel cells (μ-SOFCs) operating at low temperatures. However, comprehensive studies elucidating the interplay between agglomeration state and electrochemical properties are lacking. In this contribution the electrochemical performance of agglomerated and “dense” Pt thin film electrodes on yttria-stabilized-zirconia (YSZ) is correlated with their microstructural characteristics. Besides the microscopically measurable triple-phase-boundary (tpb) where Pt, YSZ and air are in contact, a considerable contribution of “nanoscopic” tpbs to the electrode conductivity resulting from oxygen permeable grain boundaries is identified. It is demonstrated that “dense” Pt thin films are excellent electrodes provided their grain size and thickness are in the nanometer range. The results disprove the prevailing idea that the performance of Pt thin film electrodes results from microscopic and geometrically measurable tpbs only.