LAUSR

Abstract This study investigated the effects of the apparent thickness of porous Pt cathode thin films thermo-mechanically stabilized by an atomic layer-deposited (ALD) alumina capping agent on effective electrical conductivity and electrochemical performance. Four-point probe resistance measurements revealed that a 120 nm-thick porous Pt film exhibits a relatively high electrical conductivity of 9.2 × 103 S/cm. Cathode reaction resistance measurements by means of alternating current impedance spectroscopy (ACIS) analysis show that ALD alumina can act as a thermo-mechanical stabilizer for a 120 nm-thick porous Pt cathode film. The ACIS analysis results for solid oxide fuel cells (SOFCs) with porous Pt cathode thin films of various thicknesses showed that a 120 nm-thick porous Pt cathode film is thermo-mechanically stabilized by the conformal coating of an ALD alumina capping agent. The iR-free polarization curves show that an ALD alumina-capped 120 nm porous Pt cathode film-embedded SOFC delivers ~65% higher power density than an ALD alumina-capped 480 nm-thick porous Pt cathode film-embedded SOFC.