Fabrication and Cell Analysis of a Pt/SiO2 Platinum Thin Film Electrode

A platinum thin film electrode was fabricated on the surface of SiO2 nanofibers by atomic layer deposition (ALD) and its cell performances were analyzed with an MEA using it as the cathode to reveal general features of platinum thin film electrodes. Although the Pt/SiO2 cell showed comparable performance to the conventional Pt/C cell under suitable condition in spite of the much smaller electrochemical surface area (ECSA), it showed poor performance under overly dry or wet conditions as is the case with the 3M's nanostructured thin film (NSTF) electrode. An analysis applying a transmission line model of the electrode to the Pt/SiO2 nanofiber electrode indicated that the performance loss of the Pt/SiO2 electrode under dry condition is mainly due to the increase in the reaction resistance rather than that in the ohmic resistance. The increment in the reaction resistance was suppressed by addition of ionomer to the Pt/SiO2 electrode. Furthermore, performance loss under wet condition due to cathode flooding was drastically alleviated by addition of a hydrophobic polymer to the Pt/SiO2 electrode. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.